Twin Sector is a strange game. Not because it's bad, but because it's pretty underrated and pretty poorly done AT THE SAME TIME.
I will try to explain it:
The Story: I think that was actually a good point in this game. While i tough it was somewhat pretty generic, it had some hidden potential. But i really think the story is more conceptual than a thrilling exciting story. It follows the same pattern of Portal 1. But...Worse. The voice acting is bad. I mean, BAD. Look, i can't ask good voices on a indie game (And actually, Voices are not the problem, they are actually good), but, at least, couldn't they put a little of EMOTION? I mean, the voices looks like robotic. And not robotic like GLaDOS or something. The characters just doesn't have any trace of personality or anything that make us attached to them. Not even the main antagonist or the general that tries to help us. And guess what? We have been following the machine instructions when we shouldn't. We should fight the machine and escape from its rage. Remembers something? Yeah. Story was a good point because i see they tried to do something here (With things like only putting to sleep people with talent and about what future the humanity will face), but i just couldn't be bothere remembering the characters.
Graphics: For an indie game, they are actually pretty well done. But since texture variation is not present. You will see more white rooms than anything (Again, exactly like Portal). But i could see more focus on doing models like Turrets and "the balls of death" (As i call them). But i have to admit that it's a bit strange when you look and see something is more texturized than another. If feels a bit strange, but i can forgive that.
Music: Non-existant. Aside from the game's menu music, there's no music. They tried to follow Portal and put you and a narrator, with no song. But as i said, since they have no personality whatsoever, it just feels empty. And even Portal 1 had music often. This game just doesn't have AT ALL.
Gameplay: Now, here's the big deal. The concept of Twin Sector is pretty simple: You has gloves that pull and throws. Pretty simple. You also have limited energy, so you have to make a fair use of your gloves to get through puzzles. In puzzles, you will have lazers, explosives, fire, turrets and etc. And that's where things gets pretty bad. This game is like "I Wanna Be The Guy" in 3d. You die from fall damage. You die if the "death ball" keeps touching you. You die from explosions if you are not too far away. And of course, YOU DIE FROM FALL DAMAGE. That was the worst thing they could've done to this game. Sometimes falls are not THAT big and you die anyways. And checkpoints are a mess. They're just too far away. And there just like, 3 or 4 checkpoints per stage. And that wouldn' be a problem if the design of the stages WAS A HUGE PÌLE OF CLUSTER♥♥♥♥. Seriously. Dying in this game is EASY and FRUSTATING. I can think why games like Binding Of Isaac or Super Meat Boy are frustating too, but at least they are fun frustating. This game is PAINFUL FRUSTATING. ANGRY. Angry is the definition of this. Your character is slow and it's easy to ♥♥♥♥ up. Puzzles are bad because the physics in this game is bad. 90% of times you will die because of bad physics. And the other 10% you will die from the enemies, that had to be like, the worst enemies ever. They kill you with 3 hits and only die with 3 hits too, easy, right? WRONG! Hitting them with objects is painful. They have a "recuperation time" and they recuperate way too fast. And also, if you don't grab them in time to hit them a second time (Witch makes 6 total hits to kill them), you WILL get hit by them. They are just boring to fight and are a pain in the ♥♥♥ most of the time. Mostly because there are times when they are ENDLESS. YES! They keep spawning again and again...
Now, i think they wanted to give you a challenge. But then i ask: In Portal, are turrets needed to be endless to make sure you die to them at least one time? Couldn't them make the enemies like "If you ♥♥♥♥ up and don't play the game in the right way, you lose"? Because, the enemies is just something YOU CAN'T WIN. It's frustating and keeps you away from getting past a mission, and so, from progressing the game. I never finished Twin Sector because it's way too hard from the half of the game on. I just can't win. Really. I gave up. I finished Super Meat Boy 100% but can't do the same with this game. I just can't win it...
But, remember: I said it's underrated and very unpolished. Why? Well. I liked how this game was supposed to work. The puzzles, enemies, and even the story. All of them could've worked better if they spent a bit more of time polishing it. It COULD've been a good game. But it just isn't.
Now: I like challenges. And for me, Twin Sector is a good challenge. It's like playing Spellunky from SNES all over again. And for me, it feels great. I like raging. I like failing. It means that i'm not perfect. But i'm almost sure that almost no one is like me.
So, my veridity is: If you want to challenge yourself, buy this game. If you want to find a good puzzle with a medium challenge and a great community and stuff to do, buy Portal 2.