Well, I've been playing the game alot and I have to say, I like it! With the amount of times I've played it however, I've decided to come up with a challenge that anyone could try for themselves. It consists of:

1) You can only enter through 6 star doors (yes, that includes the cat door).

2) You must have 999+ coins by the time you enter the 6th door.

Hard mode:

3) No resets or death. Everything above must be done in 1 run.

(Link for the game btw if you wish to try): https://www.newgrounds.com/portal/view/871740

I might try to do more challenges for more games (which is probably going to be mainly platformers).