I'm not really sure how I can fix this. Clicking various buttons changes what occurs for moments but it glitches out like a cartoon.
To reproduce download and extract the tar for WSL2, add the location of the folder to path and run "PlaydateSimulator"
Update: I installed the windows version (without WSL2) and the simulator runs perfectly fine from there. I don't know how this will effect my workflow though since all my files are in WSL.
Boy, there are a lot of moving parts when using WSL on Windows; graphics drivers, window managers, etc. The Simulator is using WX Widgets on top of GTK3, nothing too unusual. If at all possible, I'd stick with the Windows native simulator or use a linux VM on Windows.
After much headache as well, I just gave up on WSL. I followed the instructions here on running Ubuntu in VM and got the Simulator and development tools up and running in no time. Uninstalled WSL in a jiff and not going back there ever again.