Great to hear! Timesplitters and Perfect Dark are accidental influences, I was more trying to ape Duke Nukem 3D and Shadow Warrior Classic. I've never even played Timesplitters, but I appreciate being compared to them, it's a much beloved series.
Thank you for adding a shortcut to loop back to the start after you get the red key.
This is a major design goal that I'm going out of my way to force into the level layouts. I don't claim to be a level design guru but you can expect more of this for sure.