Sentinel is an interactive audio tower defense game. It mixes strategic gameplay with a dynamic music system.
User reviews: Mixed (29 reviews)
Release Date: Apr 22, 2014
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-66%
$2.99
$1.01
 

Recommended By Curators

"Fantastic soundtrack wrapped in a visualizing and challenging tower defense coat that is incredibly challenging and more of a puzzle than usual TD fare."
Read the full review here.

Reviews

“If you’re quite fond of the tower defense genre, then you’d certainly be wise to add Sentinel to your play list.”
IndieStatik

About This Game

Sentinel is an interactive audio tower defense game. It mixes strategic game play with a dynamic music system.

The game takes place on a sequencer-like grid. As you add defenses, collect resources and destroy enemies, musical elements are triggered in time to the music.

Fight through 31 levels to clear the virus from the system.

System Requirements

Windows
Mac OS X
SteamOS + Linux
    Minimum:
    • OS: Windows XP or later
    • Processor: 2.0Ghz+
    • Memory: 2 GB RAM
    • Graphics: Shader Model 2.0+
    • Hard Drive: 750 MB available space
    • Additional Notes: Widescreen monitor required.
    Minimum:
    • OS: OSX 10.5 or later
    • Processor: 2.0Ghz+
    • Memory: 2 GB RAM
    • Graphics: Shader Model 2.0+
    • Hard Drive: 750 MB available space
    • Additional Notes: Widescreen monitor required.
    Minimum:
    • OS: Ubuntu 10.04 or later
    • Processor: 2.0Ghz+
    • Memory: 2 GB RAM
    • Graphics: Shader Model 2.0+
    • Hard Drive: 750 MB available space
    • Additional Notes: Widescreen monitor required.
Helpful customer reviews
2 of 2 people (100%) found this review helpful
2.7 hrs on record
Posted: November 11
I have mixed feelings about Sentinel...

As a TD game, you have to micromanage a lot of little things very quickly and keep checking the upcoming waves to know how to deal with each one properly, however, unlike most TD games, the strategy doesn't come from placement or upgrading, but rather energy. In Sentinel, you have a set amount of energy (and adding a tower to the field increases that amount by 1) which you can divide among your towers, to a max of 5 energy at any one tower. You can later reduce energy in one tower to give it to another, to focus your attack on a different lane. This is the main mechanic of the game and takes serious micromanagement skills. During each round, random extra money might fall from the top of the screen for you to collect, and dead enemies might drop special icons that allow you to upgrade or buy different towers, and while the game itself isn't terribly fast-paced, all of this happening at once makes for a real challenge keeping up with it all.

Outside of the TD, there's a stage-select map, which I actually quite like, apart from the gates you have to "hack". Every so often you'll come to a locked node that you can't get past without spending a certain number of "credits". Each stage gives you 1 credit for completion and 1 for getting through it perfectly (and bonus stages give just 1, since you have to do it perfectly or fail). As you get to the later gates, you realize very quickly that you'll have to go back to some levels and get a perfect on them if you want to continue. I find this a little frustrating, as in my (admittedly limited) experience with TD games, I've never had to do a round perfectly to move on to the next.

That's about all the bad I can think of for this game, though, and there's plenty of good to mention. First and foremost, it's just fun! The music suits the game very well, going from calm and relaxed to active and upbeat as you change stages, and it's always very unintrusive, letting you focus on the gameplay. Although it does take skill to use properly, I like the energy mechanic as an idea, being able to focus more on one part of the field at first, then spread out your power later, or turn off a useless tower that round to make a more needed tower a bit stronger.

The bonus stages really make you think about every little detail of the game, from which towers to place where, when to have them on or off, how much energy they need, when to sell them, when maxing out their strength isn't a good idea... the list goes on and on, and each one is very cleverly constructed to make you aware of some aspect you may not have known before, making it a very cool way to teach the player without sitting through a tutorial. One example that really jumps out at me is a bonus stage near the beginning, where you have to collect the early enemy drops to upgrade your towers, and then sell them because the upgraded ones are worth more, and that gives you the money to set enough mines to take out the remaining enemies which can't be destroyed by the towers. If you do it perfectly, you will end up with zero money, so there is no room for error, and you definitely have to know what you're doing to get the job done.

For me, $3 is absolutely a bargain. I'm getting a fresh twist on a cool genre, and I'm learning to think in terms of what makes the most effective strategy, not just which gun does the most damage. So far I've played a little less than 3 hours, and I'm maybe halfway through all of the levels, which means I can expect another 4-5 (after going back to do everything perfectly) for my money, which is considerably more fun per dollar than, say, going to see a two hour movie for $10.

It's not perfect, and it's really frustrating sometimes, but it's enjoyable unique, and that's what I look for in a game. For the price, I have to say yes, I do recommend this game.
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29 of 36 people (81%) found this review helpful
1.1 hrs on record
Posted: April 22
It's a simple, tower-defense game, nothing game-changing. But it's still fun, challenging, and forgiving at the same time.

Here's a quick look I did of the game. Feel free to skip around to get a general idea of the game and what you'll be getting into. Or you can simply read my summary below.

http://youtu.be/UCpTb8dBmkg

I'll start off by saying it's got a good atmosphere to go along with what it is. The basic premise is that you're an anti-virus program defending off viruses, and the visuals and music that accompany it fit their their roles well to put you into that world.

The basic gameplay is simple. You have lanes of creeps that mindlessly run into your core. The bare bones of all TD games. However, the game isn't as simple as plopping down a tower and forgetting about it. You have to allocate a limited pool of power to to each tower, and the more you give it, the stronger it is. So you're always frantically shifting your defenses around as the waves progress. That means you aren't staring at the screen and letting the game play itself, which is always a good thing. You also have to click little cubes and diamonds for ressources to upgrade and build your stuff, so you always have to be on the lookout for those. The game even grants you a free limited-time tower to help clean up some of the creeps that make it through, which is also nice. Nobody likes banging your head against the keyboard as the final creep runs into the core with only a sliver of health, ruining your perfect run.

The music is also good, if repetitive, but that's kind of what techno is all about. I also really enjoy the fact that the music changes as you add power to different towers, and that when the tower themselves fire, they also add to the beat. It's almost as if you're remixing the song yourself.

But now let's talk about some of the negatives. While the game does give you a good tutorial to get you started, it doesn't do a good job explaining the newer things you get later on down the line. It's all about trail and error. You also have no idea how much of a difference you're making when you upgrade a tower or give it power. You get a visual cue that the range has increased, but not about how much extra power you're giving it. A percentage or something would be nice to have. Also, the game kept on sending in new enemies at me that I had no idea how to deal with properly. The first being a big cube that only slows down when you constantly hit it with something. But the only thing that constantly fires is the free tower that's on a long cooldown. You also have to control it manually, so you can't allocate resources or build new things until you've finished dealing with the threat. Then the game snowballs into something you can't recover from, so you have to start over.

Then there's the problem of not knowing how effective a certain tower is against a certain enemy type. I got a tower that was supposed to be effective against shielded enemies, but when they came, even at full power it wasn't that great. And when you start throwing other normal minions into the mix, you're never sure what tower you should prioritze over another as they enemies bum-rush you from all directions. And not only that, it's extremely frustrating when the tower that's effective against certain types chooses to fire at another enemy, and the one it's supposed to kill struts by unscathed. There needs to be some sort of target priority.

But yeah, all of that is only a problem if you're OCD like me and want a perfect score. There's plenty of lives you can leak before you get a game over and have to retry.

So in summary, this is a solid TD game at $3. The game offers good content, a variety of enemy types, keeps you engaged constantly in what's going on, interesting setting and music (if you like techno), and is genreally just a good time waster. Get it now, or even wait for a sale when this game won't cost more than a dollar. You'll get some enjoyment out of it.
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7 of 8 people (88%) found this review helpful
0.9 hrs on record
Posted: June 14
I got this game from a bundle.
I think the game designer put so much thought into this game, especially the bonus stages. It is like a mix of TD and puzzle solving.
A single error can make you fail a entire stage but the game just make you keep trying. Sometimes you have to micro-manage your tower down to every single shot.
Although the graphics are simple, the program has all the elements for a good TD game.
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9 of 12 people (75%) found this review helpful
0.4 hrs on record
Posted: April 22
I played this when it was on Indie Gamestand and liked it quite a bit. The whole vibe is pretty calm and chill. It's pretty much classic tower defense. I love tower defense and while this may not reinvent the genre it's very engaging and fun. The techno soundtrack is nice and I enjoyed the whole package quite a bit. For 2.99 it's not a tough decision...

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12 of 24 people (50%) found this review helpful
2.7 hrs on record
Posted: April 23
I gave the tower defense/music game Sentinel another go today, and cleared a couple more levels, but it's really just not my thing. WAY too micromanage-y for my current level of patience, and some of the visual effects that are taking place in the background in time with the music are REALLY distracting (clearly, I am now officially "old"). Maybe I'll give it another try sometime in the future, but probably not…
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3 of 7 people (43%) found this review helpful
1.3 hrs on record
Posted: May 7
If you are a fan of Tower Defence it is worth adding to your collection for the experience and style.

The Good
Great sound, theme and atmosphere. Power-to-tower allocation is an interesting twist for the TD genre.

The Bad
The difficulty curve is too steep making gameplay feel frustrating; the towers you place are never enough to handle the spawns which leaves micro-managing tower-power levels the only chance for victory. It eventually becomes a tedious exercise of sensitive calibrations within extremely limited packets of time. Maybe that's your thing, not mine.
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1 of 3 people (33%) found this review helpful
0.5 hrs on record
Posted: October 31
I normally do not play Tower Defense games, but Sentinel is a TD game I will play and play and play.
Nice blend of game play and music.
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1 of 3 people (33%) found this review helpful
2.6 hrs on record
Posted: June 21
Pretty fun tower defense game. Has electronic/techno music. Somewhat rage inducing when trying to get perfects on levels.
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1 of 4 people (25%) found this review helpful
0.5 hrs on record
Posted: June 22
Not really good. I found it was a good idea to use an audio sequencer backround (and I still find it is), but the energy system is very bad.
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0 of 3 people (0%) found this review helpful
0.2 hrs on record
Posted: June 15
Fun, but what is the song? I shazaamed it but it wouldn't identify it.
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23 of 51 people (45%) found this review helpful
0.9 hrs on record
Posted: April 22
Do not buy this game unless you love techno music, and bright lights. By love I mean, have posters on your walls of techno bands, your ipad is 3/4th techno music, and so on. The game doesn't even do that right you look at dubstep and how it has a drop and different pitches, this is more like techno generic song one A, then on to game two remix of generic song one A, and so forth. There is no other music that I came across in my hour of play, and an hour which gave me a head ache.


The music in the game plays no part in how the tower defense handles. It is no surprise that as of writing this the front page does not have a video, for it it did people would see it for what it truly is. If that's not bad enough, the back round on the screen is always exploding in some bright, in your face way with, with sound wave bars, or just odd shapes. The best way to describe this is if you have ever been to a club, stood in the middle of the dance floor, had people bumping into you, as you stare up into a strobe light and let the mind numbing, repetitive remix of the same song you heard the last 4 song melt your brain.


The tower aspect of the game alone is not too bad, it can offer a challenge, and there is a volume slider in the game so you could turn the in game music off all together, and play your own music, but you would still have to deal with the brightness.

At times the screen will also shake, making it feel like your in a boat, or middle of a club, trapped with little air, surrounded by mindless sheep.

The way the gameplay handles, is simple, but never rewards you on winning a match, more of, yup that's nice go away do the next one like a chore. I find it hard to believe even those who love techno music will enjoy this, but no doubt someone will, and be that as it may.
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5 of 31 people (16%) found this review helpful
2.7 hrs on record
Posted: April 22
If you liked super sanctum TD stick to that.
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0.2 hrs on record
Posted: June 29
An interesting take on the standard Tower Defense game. Your defense goes by the beat of the music, and the music changes according to your defenses, and how much power you divert between defenses. Very interesting and fun concept.

For example, you don't really have any music playing without defense, or power running through it, but depending on the defense tower set, and how much power you have, the more interesting the music picks up. Keep in tune and in beat with the music to optimize your defenses. A good musical ear helps with planning (make good music) and timing your attacks/defenses (but don't be foolish with where you focus, power-wise), along with a good knowledge of strategy and patience for micromanaging (It's tower defense, it comes naturally). With good enough skill in micromanagment, a good tune might come out of the blue.
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31.1 hrs on record
Posted: September 21
I am utterly in love with this game. The music is simply fantastic! (If you're into minimalistic electro/ house, that is.) So far, each stage has it's own colour pattern, looks, sound, and music. The variety has been overwhelming so far. One stage is Upbeat-House, while the next is relaxed Drum & Bass. I love it.

The gameplay is really straight-forward and maybe not a huge game-changer. But the music-creation really adds that extra sense of "Oh god I just placed a new weapon!". Which is one of the best feelings in the game, together with gathering funds and destroying viruses.

It's stressy, yet relaxing. If you're into electronic music and tower-defense games, I'd definitely recommend this!
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3.0 hrs on record
Posted: December 4
What a great surprise was to find this game in last Autumn Sale'14!

Tower defense genre, with a twist: the limited energy resource, that must be managed and relocated between the towers at all times.

Besides that, the futuristic theme is eye candy, and there is an awesome electronic music (of a style i do not know how to determine precisely if it is minimal, house...) soundtrack.

The game works like a kind of sound synthesizer, since each kind of tower makes a different sound.

I like the difficulty, and is specially rewarding when your solution is correct and the remixed music sounds good!
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0.1 hrs on record
Posted: December 14
Pretty cool tower defense game where you can actually controll the power that goes into every gun you place, affecting their range and power, and making use of a minute amount of energy; you can't max out all of your turrets and call it a day, you have to pay attention to where enemies are coming from and power them up accordingly.
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0.3 hrs on record
Posted: December 13
really cool little game, the music is nice too.
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0.4 hrs on record
Posted: December 24
No. Just no. Go away. Leave.
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