BOI Remake Idea

A wave mode where you play as one of the Seven Deadly Sins. You are stuck in a room with one door. Every 'wave' is where a new enemy (Issac, Cain, Blue Baby etc.) comes in with a random set of items. On the first wave they have no items, second they have 1, third they have 2 etc. But each time it can be a new character with completely different upgrades.

You start as Greed and go though and unlock a new playable Sin at every 5 waves you pass through. Eg. at wave 5 you unlock Wrath and at 10 Lust etc. Then on your next run you can pick each one just as you pick each character at the start of a normal run.

Obviously the way Envy plays will have to be changed but I have yet to find a good way to do this!

It is just a 'see how many waves you can get through' concept.

Can you suggest ways below on how to add to / refine this idea.

Thanks for reading - Toki.