If you find TinyVM interesting, one of my own projects might be worth checking out: https://github.com/JohnEarnest/Mako/blob/master/MakoVM.java

It's a stack-oriented VM, similarly designed to be as simple as possible, but my goal was to create something like an idealized game console. Thus, I have basic graphics support and gamepad input. The project includes a compiler for a dialect of Forth and a big pile of example code.