[PC] [2000 era maybe] basically a simple 3d mini game builder

I remember there were different mini games or worlds I could play and edit some parameters of each, like the sky box, a set of props and robot looking characters that u could change colour, make them say anything or do a few things when a condition is met. The characters were a turtle, boat, unicycle mech, a wisp, a rotating ring (more I think). The characters could shoot objects like rockets, stones, etc.

You could edit and create terrain with a brush, the terrain was blocky. The main menu had templates of the different official worlds to explore. Let me think now...the unicycle collecting stars, the turtle on a quest, a glow in the dark race event, unicycle platfomer collecting coins... This ring any bells?