Thanks! The fourth level is the longest one, yeah, and initially I had more planned for it but I ended up cutting some sections to streamline - it's probably the weakest of the bunch in terms of level flow.
The motion blur was meant to be disabled but I'm pretty sure when I packaged for linux and did some last minute bug fixes I broke that and turned it on again. I love modern technology.
I'm glad you enjoyed the game though! I spent a lot of time polishing and trying to get the core game loop feeling good, and it seems like that's paid off.