Timo 2018-10-11 15:38 (Edited)
This is just a scrolling screen and you can move and jump. No actual game. By using both BGs, cell/sprite priorities and raster interrupts, it looks almost 3D and has a water effect.
This is the first demo I programmed for LowRes NX to check the graphics system. It was originally written in C and later ported to BASIC.