There have been a few threads about it.
It's fun for teaching you how to think about programming, but actually programming, not so much.
The amount of actions you can perform is actually quite limited, sadly. If you're just a newbie you probably won't notice it, but the more proeficient you become, the more limitations you see.
My breaking point was trying to code an attack program to kill the wildlife, at which point I realized the Fire function is terrible and if you want to properly aim, you're gonna have to put in some serious trigonometry into it, but I don't recall if you could access properties of your target, like it's current direction and speed, so prediction is off, which is terrible for non-hitscan weapons.
It's also pretty low-scale, TBH. Not that many bots around to work with or a complex enough chain to use.
If you liked Colobots and want something similar, I'll recommend Autonauts:
https://denki.itch.io/autonauts
It's a very WIP game with TERRIBLE UI GRAPHICS. Seriously, it's stuff you make with Paint in a few seconds.
But teaching a horde of robots to automate several different tasks and keep a production chain is really fun. The programming is much simpler than Colobots, but you can make a lot more with it.
I guess you could also try several mods for Minecraft, with a decent enough combination being sufficient for a decent experience, like ComputerCraft or OpenComputers as the core and then Buildcraft or something similar as actuators. Mekanism and MineFactory (or equivalent) work well too.