+ Achievements was a nice touch. Well implemented.
+Sound and Music. Apart from the sounds cutting each other off they were good. Good, suitable music.
Things to improve:
+Aesthetics of the game. I especially don't like the 3d boxes. The characters also didn't seem to have jump animations (well the alien didn't)
+Controls. I got stuck a couple of times, and couldn't jump. Then when I did jump I practically floated in the aim. I feel a game like this demands more gravity so you feel in more control.
+Gameplay. The ground rising really didn't make me change my strategy from what it would have been if this hadn't been a feature, however it was good to see you adding to the concept rather than creating something exactly like other 'dodge a projectile' style games.
+Title Screen. Needs the title of the game on it....