A fun little 2D action game, though it felt somewhat light on content.
+ The game is a 2D action game. You move the character around with the keyboard, and aim and fire guns with the mouse. You also have a grappling hook that can pull or push objects, as well as help carry to other locations. You are also able to hang on to walls just by pressing the movement direction towards a wall. And finally you have a jetpack, and once you collect fuel in a level you are able to propel yourself to higher places easier. It seems to combine a bunch of other 2D action/platforming mechanics into one, and it does a fairly decent job at it.
Since you play a spaceman on a foreign planet, the controls may seem very loose. When you jump you sort of float in the air, which may be unusual for someone accustomed to the tight controls of other action/platform games. It also can get a little awkward because when you jump against a wall you stick to it as long as you keep pressing in the direction of a wall. So in the end the game does have its own feel to it, and it doesn't take long for you to get the hang of everything.
The weapons are kind of a disappointment. You start off with a basic gun that has infinite ammo, which can also be charged up by holding down alt fire (right click). This gun can pretty much get you through the entire game. It doesn't do much damage, and you'll have to constantly keep clicking but it will get the job done. You can pick up and find other weapons through the level, but the game doesn't do too good of a job explaining each weapon or its benefits/drawbacks. Plus, all of these guns can run out of ammo. So either way you'll always be able to rely on your regular gun to get you through the game.
The game does do a good job at balancing the difficulty, too. At the start of the game it feels really easy, but the later levels have a lot more to them. There are lots of enemies coming at you from all directions and you'll be floating around trying not only to dodge their attacks to survive, but also to kill them as quickly as you can. The levels are also diverse. Some of them require you just to reach the end. Some of them require you to kill certain enemies. Some of them require you to destroy certain artifacts. Some of them require you dragging space ship parts to the exit. Because of the unique character movement, however, the levels all seem big and vast (both horizontally and vertically). It almost reaches the point of confusion when you get a really big level, but it just manages to stay manageable.
In the end the game is pleasant to play through. It doesn't really grow much as the game progresses but it's still a small and fair game. If anything I'd say it feels somewhat like Super Metroid, but it definitely has its own very unique feel to it.
+ The story is just barely there. It's only told through a few pictures between levels and through the level titles. Other than that there's no text or voice work.
Basically you are out in space and your spaceship crashes on a foreign planet. You must explore the planet, survive the hostile creatures there, find your crewmates, assemble a new ship, and escape. That's basically all there is to it. Just some explanation of why you're going from point A to point B.
+ The graphics are pretty good. They definitely have their own art style to them which is pleasing in its own way. What I disliked, though, was how easy things tended to blend together. It's hard to distinguish foreground from background and enemies from the environment. I think the colors could have been adjusted to enhance this distinction. But that's about all I can complain about. Everything else felt and looked smooth.
+ The game can easily be completed in under 2 hours. Granted, you can go back and replay the levels because you are rated on each one (how fast you completed the level, how many deaths you had, how many secrets you found, and at what difficulty you completed the level). So if you wanted to, you could go back and try to get maximum stars for each level. There are also a few extra modes that basically change a few basic things for a challenge, but I didn't explore them much further.
I think that $10 is a pretty high price for this game. The game itself is simple and fun but it's really short and I doubt many people will keep playing the game after they beat it. So if the game goes on sale then I would recommend grabbing it if you want a few hours of 2D action/shooting. But I'd definitely discourage you from paying full price because the game does feel light on content after you complete it.