I also have to admit that I play the prototype version much more often than the new version.
It kills my resources, the laptop gets really hot (and loud!) and I don't think that Unity was the right decision here.
But somehow, the prototype is more relaxing. Goals are clear. And buildings aren't changing through the game.
I played the version on Steam. And through Netflix, I played the mobile version. The demo on Steam for the new version was really more than I needed. The mobile version is crashing about every 50 Seconds, it's no fun in any way. Levels can't be completed mobile - I'm really glad someone thought about that debugging menu.
Buildings are changing about every second level, so you have to start over with learning. Goals aren't clear and hidden somewhere in that handbook. Graphics aren't everything for a game.
Prototype: 4 stars out of 5. If it wasn't that resource hungry, thus bad for the "real" nature, I would pay for it.
Full version: 2 stars. Same as above. But also the new buildings would have to be introduced "softer". Goals shouldn't be hidden in the handbook, but instead shown as in the prototype. And the mobile version would have to be rewritten from scratch in a native language. And no, 25 € is too much. It's just a few hours.