Playdate development has been a great experience. The limited colors and RAM helps me reduce my project scope such that I would actually finish them, and the limited CPU makes optimization exercises more rewarding. And it's not just all constraints either -- the sound/synth system is quite nice, and the crank is fun input method that takes some hands-on experience to fully appreciate.

The only downside is that there are still relatively few people with Playdates, and that puts an upperbound on how many people get to play your games.