Liked it
Cool game. Good graphics, good sounds (liked the radiovoices), well made. I especially liked the upgrades and that you could use them all at the same time. The field became a bit of a mess though, you really couldn´t see the enemy bullets anymore. The bombs were the best in my opinion, the other weapons didn´t really seemed to have much effect and it was a little hard to hit the tanks on the ground with missiles. A power-up I missed was the extra life, not sure if you added that one or not, but I haven´t seen a single one after 30000 points (which was my highscore). If you haven´t added it, please do.
I think the only way of improving this game is by adding a story, levels and bosses etc. Just a simple story is okay. I wouldn´t add that many levels either, just a few and a couple of bosses (heavy machineguns and stuff like that). I think your game will be a little bit better then.
Overall 9 out of 10, 5 out of 5. Well I really enjoyed this. Just a simple game, blast everything that gets in your way =) I hope you´ll make a few more of these. Keep up the excellent work. Oh and by the way, I could barely hear the music while playing cause of all the firing, explosion etc. noices. If you want people to hear the song, try making it a little bit louder.