Okay, I got sub-3:30. I am satisfied now.
This you? https://www.speedrun.com/just_one_boss/run/zplw07xm
Oh no, I didn't realize there was an official leaderboard xD Sadly I didn't record it for upload
I just accidentally discovered a glitch that makes it possible to beat the game way faster. I'll see if I can do it and upload.
Looks like other people already knew about it :( I thought I was being clever. Oh well, still submitted to the leaderboard and pending moderation. Thanks for the game, super fun!
