I bit the bullet and used Custom Mode to complete a run. Don't look at me like that, I put 16 and a half hours in, I played more than enough to form a solid verdict.

But yeah, this game's great. It's easy to see how it really helped push the deckbuilder genre forward in the video game world. Just prepare for it to bash your skull in a little bit. Every time you feel like you're properly learning how to surf, expect it to push you into a tidal wave.