That's awesome! I am super happy the very first FPS you've played was mine! If you need any help on it just hit me up!
If you don't want to get freaked out, try Purple Arrows. It's not a horror game, just a standard shooter. Sector 12 is a a horror game and S.C.A.R.E.D. Hour Zero is also a horror game but focuses more on combat with humans than monsters, but the game is a bit glitchy and bugged in the last few chapters because I haven't had time to patch them lol