I'm happy to that is how you got this working. The way that I've been building out the code would be really similar to what you described. I didn't even think about using a dictionary with the grid manager. The way I was considering doing it was with Area2Ds, though making them like a puzzle piece that slightly overlaps into the neighboring tiles. The tiles would also have another Area2D to mark off the tile as being used. I've already started with the puzzle piece method so I after I try that out some more I'll get back to you oh how well (or horrible) it worked.
Honestly though, I really want you to make more of this game. I've been playing it for totaling over a couple hours now. Have I beaten it? No... Have I gotten close just for RNG to give me the finger? Many times. Still with that, I can't get enough of this game. The cozy music, the little sprites, the sound effects, the way it makes me think. This is honestly my favorite game in the Jam thus far and I am skeptical of another taking that place. It just scratches so many itches just right. Your game is REALLY GOOD!
Viewing post in Cards of the Scaling City jam comments
I'm definitely thinking about it. There's a lot more I can improve; UX, polish, a discard mechanic, more policies and cards, actual Balatro-style boss fights... Not sure when or if I'll do it since my current main project is getting really close to having it's first world content complete and I can actually start thinking about making it public, but it's definitely on the table!
I'm glad you've been enjoying it that much, though! I'm honestly really proud of how it turned out even if it's rough around the edges in a lot of places.