In many ways, this sci-fi, shooting, dungeon-crawling RPG reminds me of "Virus Hunter," a walk-through example used in the Game Design program of "Cybercamp," which I enrolled in when I was 10. Is there some common inspiration I'm not familiar with? I highly doubt Virus Hunter had much originality...
As a comic side-note, I initially thought the Light weapons meant they fired light as their projectile.
P.S.: I must compliment the decision to jump straight from one mission to the next. I initially told myself I'd stop after beating mission 1, but, with the game offering no natural breaking point (e.g.: "Congratulations! Save and continue?" or some other kind of pop-up exposition or prompt -- an analogous phenomenon: it's easier to put down a book between chapters than one paragraph into the next chapter) , I found myself telling myself "I'll stop after beating this mission." As mission 3 rolled around, I found it hard to force myself to quit. It's the game designer's job to get the players addicted, and you certainly succeeded there!