@Roosterhead you can't shoot with w. I guess you read it in the description and i suppose that was a typo but in the game tutorial it says you can shoot with "x,y,z" not with w.
Now for the review the game is really easy i beat the 10 lvls in the first difficulty without buying any upgrade at all.
The game is a little boring, the background is just bad sometimes is hard to spot yourself in that white background.
Finally maybe is just me, but i hate when luck is a big part of a game specially a shooter and the boosts you get from the enemies are so random. That takes away the fun for me.