This "Complete Pack" contains the first five full Keen titles, excluding Keen Dreams and Aliens Ate My Baby Sitter! probably due to publishing rights issues.

Commander Keen in Marooned on Mars:
The first entry into the series, and a very enjoyable one. The difficulty isn't too high or too low, just about right; it's short and sweet. Despite the lack of music and somewhat annoying sound FX, the title still retains a lot of its original charm.

Commander Keen in The Earth Explodes:
Out of the original trilogy, this is my least favorite one. Why? Because it's basically the first one, but quickly loses its charm when the unfair gameplay kicks in. And I don't mean "unfair" as in "challenging", I mean unnecessarily aggravating. This is due to the tad bit of input lag, bull**** level design, and annoying enemy AI. Thanks for that John Carmack.

Commander Keen in Keen Must Die!:
This entry is even more unforgiving than the second, and the lack of music and sound FX REALLY wears on you by now. Why isn't it my least favorite? The main antagonist. Without spoiling anything, the main antagonist and his simple (yet relatable) backstory make the game worth seeing through to the end, and you barely even learn anything about him until the boss fight, which luckily, isn't too hard. I'll just say.. it shows a lot of humility for id Software, considering how they went on to turn the entire industry upside down multiple times.

Commander Keen in Secret of the Oracle:
This is probably my favorite Keen title, why? Well, one reason is Dopefish's glorious debut. Another is how nearly every aspect of Keen was improved vastly. This is when the Keen series felt much more like a fully-formed franchise rather than a labor of love from a group of eager programmers. The graphics are much more colorful and cartoony, the gameplay is MUCH more fluid and MUCH less aggravating, and there is actual background music that’s catchy and makes the experience more enjoyable. And you can't forget Dopefish, we will never forget Dopefish.

Commander Keen in The Armageddon Machine:
A lot like Secret of the Oracle, except new levels, music, easter eggs, and sadly leaves on a big cliffhanger, and I only mention this because the sixth title is not included leaving you to find it yourself. Still a lot of fun and pretty enjoyable. The only nitpick I really have is how you actually beat the game, as it is very confusing and very hard to actually figure out how to blow the last fuse. Otherwise, a solid Keen title.

Some people complain on how "You're paying for an emulator!" or "It's missing two episodes!” I really don't. This is the bulk of a classic series, and you're paying how much? Five dollars? And you'll probably wait for a sale anyway, won't you. You should be grateful it's even on Steam for legitimate purchase. Also, the games run almost flawlessly in DOSBox, unlike many other DOS games released on Steam packaged with DOSBox..
If you want to explore id's past, want to dive into another retro platformer, or simply just bored, buy the pack now for five bucks. Don't even wait for a sale, it's not really worth waiting for when you could be playing now.

This is a great platformer that was released a long time ago and re-released on steam.
I owned them back in the days and I played them to death, so I was happy to see them on steam as well.
The only downside : keen 5 and 6 are sadly missing..
BUT it has a pogo stick!
10/10 would pogo again

mother ♥♥♥♥ing amazing game

Commander Keen is one of the earlier non-sports titles by ID Software (creators of DOOM) and is a childhood treasure of mine. Without going into detail, Commander Keen is a simplistic sidescroller in which you collect candy and kill aliens. These days it often difficult to find entertainment out of such a simple game, but if you are on a pilgrimage to find ancient games or simply enjoy the retro, 8-bit style, Commander Keen will be an enjoyable experience for you.

P.S. The Galactic Alphabet used in Commander Keen has become a cult iconic language, appearing in many games since, including being featured as the enchanting language in Minecraft.

This is one of the first games I played. Well, to be accurate, Commander Keen 4 is one of the first games I played.

When I first got it through Steam, I was worried that it might not have stood up to the test of time. Some games do, some games don't. I was ecstatic to find out that it had. The animation, humour, simple yet enjoyable graphics and sometimes frustrating gameplay were just as good as I remembered. This series brought us the Dopefish, which by itself gives it a big thumbs up from me. But more than that it gave me something that was, as the saying goes, easy to pick up, but difficult to master. My only question is this; shouldn't there be some new 2D Keen games for us to be enjoying?