Here's a little 3d heightmap builder and visualiser i'm working on at the moment, first ever pico8 project and i'm having a lot of fun with it. I'm planning on turning it into a little walking simulator with more to look at eventually, but for now this is all i've got. There's a lot of work to be done in terms of optimisation first.
The controls are directional buttons to move about, and directional buttons+z to pan and rotate the camera.