10/10 for me.

The Co-op Experience: Yelling at each other to wait before using debuff cards, but nobody listens, they just keep nuking with everything they've got.

The Map: Mostly used by my guys to draw giant genitals.

The Loot: Choosing relics is fun because you all need to pick different ones. If you click on the same relic, the game makes you play Rock-Paper-Scissors to settle it, which is nice.

The Strategy: Communication is key, especially in late-game content. Coordinating your build plans adds an incredibly complex new layer to the game.

The Core Game: Aside from co-op, Slay the Spire is Slay the Spire: the absolute best, here with great additions and improvements.