I had fun playing it on PC, but the game is just that much more fun and immersive on the Deck. I'd say it's the first game where I've noticed a big difference since I got my Deck last week.
On the other hand, I found Slay the Spire to be better on PC. The controls and smaller screen seem to get in the way a little bit more.
Any other suggestions for games that really shine on the Deck vs PC?
If you enjoy card games (you mentioned slay the spire, so I assume you do) then I can also recommend Monster Train. Pretty fun to pick up for short sessions, runs great too.