Mine has to be Dragon Quest: Rocket Slime, a DS spin off of the Dragon Quest series that sees you playing as a slime operating a tank and rescuing the people from your town. You run around the overworld, collecting items to use as ammunition and saving money to upgrade your tank. The art and music are just as great as you’d expect from the Dragon Quest series. It made fantastic use of the DS’s dual screens. It’s also written for a younger audience, so a lot of it is just really silly and fun! Try it out for sure, I’m so sad there’s no sequel :(
Endorfun. I got it for Christmas in 95 or 96 and would spend hours playing it. Years later I would get emulators to continue playing it. Introduced my college roommate to it. There were times I couldn’t get the sound of the animations to work, but I kept coming back to it. Every now and then, I’ll revisit it. Wish it would get a rerelease or new version, maybe something I could pay on my phone. Loved the music, the moving colors and textures. It has a therapeutic way of getting me out of my head.