I’ve been playing for the last three seasons now. I was going to break my F2P status to get Ghost-Spider but the decisions made by the developers the last month or two made me decide full-out against putting any money into the game if they don’t pull their heads out of their ass.
No ranks. You get paired against an opponent and you two play until someone gets 10 cubes. If you win, you get some extra rewards (some coins for a new shop that was added with the mode) and a ticket to move up to the next bracket. Higher bracket means more coins for winning, but also more wins required before you can advance to the next bracket. 1 win, then 2 wins, then 3 wins, then 5 wins. If you lose, you go back to the bottom bracket and work your way back up.
It’s pretty much just regular snap but 1) no ranks to lose, 2) an extra currency that you get as you win, and 3) you play the same opponent a couple games in a row, so you can start strategizing after the first game since you know what deck they’re using now.
You still earn boosters and complete missions in the new mode, so if you’ve hit infinite already there’s largely no reason to not play the new mode.