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 :(
Nice man, I failed to mention also; you can host your game online so playing with friends, or having the game open is a thing. It’s quite fun when someone joins the enemy team, they provide that little bit of spice to an otherwise, potentially easy mission. Doubly so if they comandeer a tank or something - uh oh!