Fun take on the theme. I've seen  deckbuilders that combine tetris with deckbuilding but this is the first one where the cards have adjacency bonuses. Really adds another dimension to  the planning.

The adjacency effects are cool. It's a bit hard to keep track of them since the colors are written in text.  You can embed the icons in the text (ex:  🟦nimble x1 ) .It's doable in unity but not sure how easy it is in godot.

I'll say that it's a bit odd that it's tetris but there's no reward for filling a row or grid. Maybe I didn't find any cards wit h that effect. But it's a situation that the player will naturally create during gameplay so it would be best to reward the player for it

My other suggestion would be that the game takes a bit long to get going. Enemy health starts off very high in the first battle. Sure, it's hard to  lose but you can't do anything interesting other then maximizing grid utilization.  You don't get cards with bonus effects or enemies affecting the grid until then. I think either a shorter first battle or introducing the subversions earlier will alleviate this.

The graphics are nice. I like the cute little kobolds.

The music is a bop. I had it in the background while I was writing the review and it's so good that I'm leaving it running afterwards.
Overall this is a great entry,

Pretty fun fellow godot user!

I love the gameplay loop

I found a bug/s: If you drag an item while your turn is ending you can put it on the board still, and if you put that item into your hand you cant play anymore hahahaha

Otherwise its solid! :)