Hi there - thanks for playing and for your interest in the game. I'm hoping to get this one done by end of 2022! (wish me luck)
New Game+ lets you bring in any upgrades you may have purchased from the special vendor in Area6, and it also brings over any Champion's Medals (the main upgrade currency) from that save file, so that if you're working towards a bigger upgrade you don't have to collect all the medals in a single run.
There are other ways to earn upgrades but most of them are through the special merchant for the moment.
I hope that helps!
