Okay, This is all I've got so far. Levels 1 to 4 are done (final game should have 8 levels). You can continue playing after level 4 but the levels will be mostly empty.
I might have been a little bit too ambitious with this game, oh well...
I won't be able to work on the game next week, I think I will have it finished by june 20th or something.
I know the game is a bit difficult right now, I'll work on that.
* Level 1 needs much more variety to be genuinely engaging. There's only one kind of obstacle?! Moreover, they seem to be distributed too consistently over the level - there's no real difficulty ramp within level 1.
* The spinning bullet turrets seem to be less threatening than the standard bullet turrets, since about two thirds of their bullets are sent in entirely the wrong directions.
* The sliding shields and the laser turrets were a welcome addition - the shields, I feel, should have made a showing in stage 2. Also, these things really shouldn't just be dispensed randomly, as it seems they currently are. Placing them with diligence and care in several varied combinations could really make a memorable level.
* Also, the powerups should be released with more consistency rather than at the capricious whim of a trickster god.
* The health powerups should probably not have "H" for health (moon buggies can't really be called "healthy") so maybe replace with a less specific "+" sign.
* You shouldn't end a level when there are enemies still on the screen!
* The ground is a bit too high-contrast. It doesn't look as flat as the gameplay and tyre tracks suggest it to be. I recommend dulling it or lightening it.
* Some small bugs: the tyre tracks aren't quite aligned with the tyres, and I somehow destroyed a turret base without destroying the turret gun. Also, the explosions don't move with the scrolling, so they incorrectly float forward with the player.