I'm glad someone is still doing light-gun style games! This reminds me quite a bit of the on-rails Resident Evil games for the Wii. The backgrounds are great and I like the variety of enemies and items you were able to add. I was a bit confused why two different humanoid enemies would have different weakpoints since I came across one that seemed to take more damage from chest shots and one from headshots. I think some kind of visual cue could help with that. Still, really fun experience!
FYI - The game tried to launch with SteamVR and gave me an error that my headset wasn't connected. SteamVR doesn't normally popup for me unless a game tries to run in VR mode so there might be a setting in your project that needs to get disabled.