When i was a kid (maybe 10-11-12 years old, im 21 now) I used to play an online flash game which was a sci fi FPS shooter where you played a lone soldier tasked with clearing out an entire space ship full of aliens. You started out in the hangar bay getting out of your shuttle and with only a pistol, as you progressed you pick up crazier weapons and fight scarier and tougher aliens. It was a pretty vast game, with good graphics for the time, an ammo/inventory system i think. I know it used Java or Shockwave. I would love to find it again, thank you!
Registered just to give you an answer after all this time, idk if you found it. The game is called Alien X, I've been searching for it myself. Should be able to play it here: http://www.gamingcloud.com/game/alien-x.html Enjoy!!