Two small suggestions...

[VPaulus]

You're in a phase that is only polishing and balancing, but we're here also to suggest, in our opinion, small improvements to the game, while hunting bugs.

Anyway the first one is about the tip system. IMO those question marks are esthetically speaking ugly. Why not removing them out completely and just let the "balloon" with the tip appear, after a very short delay, when we hover the proper option?

The other thing I'd like to suggest is, whenever we select anything with the mouse button, I think, we should here a quick click sound. It would help us to acknowledge that we have done something. Sometimes I'm pressing but I don't have the feeling that I'm pressing and selecting, like if it was "stiff".
I'm not sure if I'm being clear enough for you to understand, but English is not my native language.

Anyway these are small things.