I found this games on synaptic. Which is interesting, because 1 it is a 2d shooter. 2 it is really different. And did I tell you it is free, as in free beer and speech.
It is a game by Saba. He is a game creator that create game, that is simple. And with very interesting graphics too. Not to mention very fast pace.
A few game that I will actually recommends is:
1) Gunroar which is a shooter, with you as gunboat. Sinking enemy fleet.
2) Tumiki fighter features a world build on toy building blocks.
3) Titanion, is a game ala gatagga. just more fast pace, and more nicer graphics