Thanks for the feedback! I'll fiddle with the platforming physics. I suspect it'll take some iteration to get it right. Also noted on the save file problem.
For the resolution, how did you set it to 16:10? The game is supposed to add black bars to crop the aspect ratio to 16:9 whenever the window changes size. If your monitor is 16:10, maybe there's an issue with cropping the aspect ratio in fullscreen... I'll check.