Eh.

Minor gripes:
Since you can only jump over two blocks, you can get stuck in the four block high pit in level 2, this can be solved by pressing R (but strange that the pit doesn't just kill the player, since it will force you to go back to the beginning of the level anyway).
You often only jump two and a half blocks wide, making platforming feel wonky, you can jump three blocks wide but only if you jump near the edge (risking to walk off the block too soon whilst holding right/left).
You can jump past all the enemies as they only start shooting after you stand still for a bit.
Shooting was a bit boring (since all enemies take three shoots, and you can only reload after using all those three shoots), so I found that the grenades were way more fun to use, shame there was so few of them (also only being able to hold two grenades, when there already are so few to begin with).

Great demo but a bit short.
Loved the screen/level transition, it looks neat.

Game is pretty good as tech-demo, but definetaly should be reworked a little bit.
Grenades are pretty pointless, because it's always eazy to shoot enemies one by one, 3 bullets are always enough.
As unfinished game, it does not offer any challenge. When you die, you just need to run trough empty level, which is pretty boring.
But, overrall, it has potential, so good luck with it

If things are going to get crazier in later levels, you really need to ditch reload. Otherwise, it's looking good. A timer on the grenades would be useful.