Someone else in this thread made me aware that there IS a sequel on the 3ds. It just never came out outside Japan. However there is an English translation ROM, so if you wanna play it bust out the emulators!

I'm starting up og Rocket Slime again right now and it's still just as great and charming as a I remember it. Maybe a little simple, there are times you can definitely tell it's made for children, but it's one of the few non-nintendo games that have tapped into that amazingly childish energy. I typed in my name and slimes made my name on the top screen! Or can't forget about The Plob, that name alone makes me crack up