Download Special Force
Special Force is a first person shooter that gives you a clear objective throughout the entire game, even though there are only three levels. At the end of each level you will have to beat the boss in order to take him down and advance to the next level.
Besides the boss monsters you will also encounter all kinds of other enemies, including even humans that still must be killed. You will have to move fast in order to protect yourself from the enemies and you will have to shoot even faster in order to take them down once and for all.