I played a couple of runs of your game. Never got very far, but I really like what I've seen. This type of game seems to be what the Playdate was made for: Quick to pick up and start a run, but deep and varied enough to keep me coming back.
I also love working with those specific constraints - and trying to break them. For my Roguelike I heavily rely on the fake function calling you describe, it will allow you to do some pretty amazing things. I also tend to use rect() a lot, but that can kill performance quickly.
If you're interested to see where my Pulp Roguelike project is going, you can take a look at https://mastodon.gamedev.place/@Braininabowl. I'm planning to resume working on it once I've cooled down from the 7drl.