It's an amazing game the knife powerup seems to be underwhelming the minute i got it there was only atleast one instance where it was actually needed and that's at the knife chest to get rid of the frogs, by the time you get use to the knife the difficulty has already sky rocketed.
The knife powerup has a small hitbox allowing you to miss enemies easily it also has little to no info on it. Finding out the knife could move object took way too long i know anyone could find out you need to hit the pillar with the knife but to even test to know if it's possible you need to move to the further right of the screen and see that the pillar can move. Then jump back to the further left and jump the highest you possibly can to the left from a tiny platform unto another tiny platform while throwing your knife at the highest point of your jump.
The knife's hitbox should also be able to hit bats or any creature at the same height as the character to prevent blindly jumping unto a platform and having a bat hit you out of nowhere cause your trying to outrun the other hazards
TLDR: the knife powerup was horribly introduced. my opinion ofcourse