I'm wondering about 100% because the rules say to complete all ingame achievements and then kill "space worm... thing" but one of the achievments is collect all hats, and the last hat is given after reloading the game after killing "space worm... thing" once. Do we then have to wait through the credits and kill it again? also is it required to delete the file in explorer manually or can we just delete the save through the game and record the process? Thanks in advance

The latest update allows you to skip the intro cutscene and credits after having watched them once. Hold down your interact button or mouse to skip the credits

Unfortunately you have to delete those files in your file explorer. Yukon wrote the rules so the devs better have given us the right information.

I'm going to ask again here because of the new 100% WR, but do we have to kill the "space worm... thing" once or twice? I only saw it done once in that run. I'd like to know for if I do the run again

I haven't studied 100% as of yet, but I would assume there are no quest turn ins that require you to beat the final boss, so only doing the event once is necessary.

Yes that is correct you can get everything done before beating the final boss

I'm gonna pop this question here for you 100% runners. Should we count it as 100% when the "Completionist" advancement/trophy/notification pops, or do we still require purchasing of all powerups?

completionist only requires all tasks, I'm saying all achievements except high fashion need to be acquired in the run. I'm excluding high fashion because it can only be acquired after reloading the game after defeating space worm due to the 2 hats it gives you.