Thank you very much for your time you put into your comment! It's really welcome and helpful.
You are right with the AI.. basically there is no "AI". I tried to implement some sort of pathfinding in a later version, but I wasn't satisfied at all and left it like this. It will be improved for sure in a newer version. I also agree with all the other issues you mentioned. Most of them I already noticed and noted. But some of them are actually pretty smart and will go directly to my todo-list.
Unfortunately, I can't currently put the effort into this game as I wanted to. But there will be a new/better version for sure. It's just a matter of time. :)