Alien Slayer 3D Amazing!
This game does exactly what a first person shooter should, but there are a few things you can improve on (only a few).
1st: Different enemies if possible though I noticed more are added over time which is good
2nd: Different weapons, though not necessary, make a better game.
3rd: If you don't have one already (I'm not that far yet) add a boss battle
4th: This is a small glitch, but if you shoot of an rpg and switch to pistol it is considered a survivor kill.
Even still this game is fun and is a major improvement on what you had before Keep it up!