[jerf]

A Minecraft-based Atari 2600 emulator was running about 1 frame per second last I knew: https://www.youtube.com/watch?v=mq7T5_xH24M

And that's heavily based on internal scripting with real code.

The recent "Minecraft"-in-Minecraft emulation was done with pure Redstone internal to the game, but has to be run on a specialized server that accelerates Redstone operations by several thousands to be even fast enough to record time lapses at a reasonable sped.

In-game simulations of logic gates that are generally running at fractions of a Hz are a pretty steep obstacle to overcome for any "real" computing like that. Just to calibrate your expectations.