I have an idea: fickle crates. I think it will be fun. Odd moves it can be pushed, and even moves can be pulled. That is, at first it can only be pushed, then it can only be pulled, then it can only be pushed...and so on.
I don't really get it why there are people taking ideas from Increpare, but I'll make it at some point.
Sorry, I didn't know this idea came fromIncrepare. Maybe this is a very common idea? I'll try to come up with a unique one.
You already sent you idea. Wait for someone else to send an idea to send yours.