Yeah I made the buffer for dropping through platforms a bit too long I think. I also forgot about jumping for WASD controls (I nearly forgot shooting with WASD controls and added it last minute), so I'll address that in the patch
Colliding with the side of platforms is a glitch I've noticed in my other games and I'm not really sure how to fix it, though there's probably some way, I'd need to look into it more.
Sorting the achievement list is also a good catch, I'll add that to the patch as well, should work well alongside the new hint mechanic from getting enough achievements. It's funny how you mentioned obscure secrets like in Deltarune since I wanted to reference the Forgotten Man but it would've been too esoteric even for something that didn't change the achievement totals and I ran out of time.
Thanks for the in-depth review, and I'm glad you enjoyed the game!