1) What do the powerups in Granny's store do?
Are they bought at that price or is it an unlock system?
(ie either item A $500 + item B $1500 = 2000 or item A + B when you reach 1500 coins)
2) Is there any instructions/manual for this game?
I only found out by chance that instead of letting go of jump to stop the jetpack/hover, you have to press jump a third time.

Also, is the Powerup Shot actually a powerup? Or is it just a glorified key taking up space? If not, how do I use it?

Plus, the high-jump is finnicky. Any tips on how to use it properly? Or is it nerfed?

So, I've finished the main game 40/60 sprites, 2000 gold. Still no idea how to unlock Granny.

Also, what I've found out:
The shop is an unlock system. Also, you can only have one powerup at a time.
The Power Shot unlocks doors and fires further.
The 2nd powerup allows more hover time.
The 3rd powerup is an insanely-high-jump.

Unlocking Granny:: - I looked it up online. Yes, you need to get 40/60 sprites and 2000 gold.
What only 1 out of 10 people tell you is that you need to quit to the Title Screen and press up to change characters.
Also, Granny has all 3 powerups at the same time.