Gameblabla has released Crafti which is a Minecraft Clone For Dreamcast, the game that has sold mega numbers and even my 6 year old who has autism loves this game, heres a little more details:

Crafti for Dreamcast is a port of the original Crafti - a Minecraft clone developed for Texas Instruments TI-Nspire graphic calculators. There is no music and there are no enemies (so don't go expecting to be chased by a Creeper), but as a proof of concept this is pretty impressive work. There are numerous different block types, including familiar types like water, lava and even explosives and switches etc.

More info here -->