Cosmo Blaster is a buy to play game on mobile devices that is very affordable, and that makes sense considering the game isn't exactly very complex. You just fly around on a little space ship, shooting asteroids and picking up boosters like ammo recovery, shooting speed boosters, fuel, shield and the triple shoot as well as health boosters. If you get hit by an asteroid it's game over.
This is a fun game even though its very simple. I think this would be a fun time killer when waiting for others to arrive or perhaps on the toilet, but I don't think this would be a game you could play for long periods of time, unless you're trying to chase your latest high score.