Really fun game! It has great art and music, good platforming, and the concept of the game is really cool too.
It's quite easy to just complete the game normally, so aiming to get the achievements is a really good challenge. I have made the mistake of going for a Full Score and Pacifist run at the same time (because why not) which pretty much resulted in me losing my sanity. It is not impossible, it's absurdly difficult but still very much possible.
So if anyone is thinking of doing the Full Score and Pacifist run at the same time, please don't. Don't end up like me, save yourself. Unless you want a challenge, it is much easier to do it on separate runs. I kinda wish this kind of run was on the leaderboard though, I'm pretty interested to see how fast people could do this.
edit: I actually did it! Took an embarrassingly long amount of time but still did it! I still managed to do it in under half an hour (although the record says 32 mins but that is because I had to make some food and I couldn't pause the game haha). But it just proves that it is definitely possible.