donation box is for..?

[Artur]

what does that do, the donation box in the shops?

[Yes]

unlocking items

[Rin]

more money you add more things the shop can carry

[Gallant T Derg]

The Donation Box serves to unlock more space for items in the shop the more coins you deposit. The new items you can get are the Black, Red, and Blue Candles, the Blue Map; which shows the location of Secret and Super Secret rooms, and the Stop Watch; which slows down all enemies.

Also, the Donation Box is a sort-of makeshift bank that you can bomb to get some money if your short a few coins for something in the shop.

[Hexeract]

Filling it past 999 has an extra surprise too.

[Solo Death]

Unlocking about half the shop items, as well as better shops in general. It's worth it, 999 unlocks arguably the best item in the game.

[Artur]

ty