Good game! The controls are pretty fun. I'm excited to see more features developed into this concept. :D

Needs map, auto-fire for assault rifle, more plot and cool ghosts.

This game needs a lot of polish and fixing. The performance drops really low every time I enter a fight (might be my poor PC's fault though), map generation works really weird, creating either huge empty rooms or places filled to brim with enemies. But the biggest issue is the broken aiming mechanic. For some reason my aim doesn't follow the cursor and the gun easily gets stuck in one of like four angles: up-left, up-right, down-right and down-left. It's so frustrating.
The graphics look nice, but could use more variety. Honestly, everything needs more variety - guns, music, enemies, NPCs, pickups, etc. But yeah, I understand it was made for a game jam, you probably didn't have much time. You could also add some introduction to the game, since we're just thrown into the mansion without any explanation as to why am I here and why do I have to talk to weird ghost NPCs to open the portal to the next level. Last thing I want to talk about is the lack of UI. No ammo counter, no map, not even an indication of how long till your gun reloads. These things would be really useful.
That's all. I do like the idea of this game, but as I said, it needs some work. :)

Weird bullet patterns and bullet colors unfit for a haunted dull sort of mansion