In closed beta currently - disclaimer - I haven't actually played it ( I have too many games to finish to play beta stuff ), but sadly I've watched more hours of people playing it than I've actually played anything recently.
It's kind of like a weird combination of a card game like magic, with a roguelike autobattler. The asymmetric pvp kind of appeals to be, given pvp isn't really my thing, your mileage may vary on how much you want your opponents to suffer/how bad you feel at getting your ass handed to you.
The gameplay for the three heroes they have at the moment is wildly different, with a lot of neat mechanics - like the pig hero that gets various items that grow more powerful as he buys and sells stuff, or the mini-robot that has to build around a particular fixed item called a core, which sort of forces different playstyles on which one you choose/get in a run.
Free to play with 'founder packs for beta access' made me immediately suspicious, but it appears from what they have done so far that their monetization model is:
1) PVP glory ( pay money for ranked tickets to get a PVP rank )
2) Cosmetics ( ranked game wins give chests with cosmetic items etc )
3) Heroes ( buy a new hero with their own cards etc ).
Of course, that may all change when they get greedy or desperate, time will tell.
I can't really say what about it appeals to me, but it just does.
