It took me awhile to get my bearings on this map. I start by grabbing yellow key. You can get lucky with the elevator and save a few seconds which I don't get.

I go to secret spinning room next. If you stand in the right spot you prevent an enemy from spawning. This wait is faster than going the other route.

Switch lowers final elevator but you still need blue key to drop the bars on exit. House next door has the switch to access blue key area.

On way to blue key you can make a faster jump at top of stairs but if you miss it's a reset so I didn't go for it.

Blue key grab was kind of annoying. Door drops when you grab key and you want the big enemy to block it until you can escape. Problem is he can still move around so I think you just have to get lucky. I think door is on a 10-15 second timer so having this at the end of the level sucks.