This was originally meant to be a digging/building game with some survival mechanics, but I kinda got carried away with adding nice grass.

There is an axe on the ground somewhere if you can find it between the grass. You can even smack trees with it (they don't fall though).

Left click digs into the ground (while not carrying the axe), right click places a platform. E lets you pick up items (as in the axe, there are no other hidden items in this grass field), G to drop. Space to jump, Ctrl to duck, C to toggle zoom. Escape to unlock cursor, F11 to toggle fullscreen.

Didn't have time for the water, so it looks like a blue plastic surface.

It is running in a self made lightweight engine using C and SDL3 GPU. The most expensive effects are the grass (of course) and ambient occlusion. It runs at 60 fps 1080p on my GTX 1050 from 2016, so with any graphics card less than 10 years old you should have no problems.