I know that it's not in development any more but I figured I should still say something. On mac when I went to open the app it said that 

“Tilemancer” is damaged and can’t be opened. You should move it to the Trash.

Clearly there is a problem. If anyone has a solution please help, it looks like a really helpful tool.

Wine?

Nope, I tried installing old mac versions, with no luck, I tried installing old and new Windows versions with Wineskin, also  with no luck. All the applications just give some variation on the error message, "This application is broken, close or move to trash".

Try opening Terminal and running :

xattr -dr com.apple.quarantine /path/to/Tilemancer.app

This is just a Gatekeeper problem; the app isn't actually damaged.

I don't know what the difference is but when I went to try the Terminal command I first had to reinstall the app (because I had deleted it after it didn't work). I downloaded it from the itch app, not the webpage and after I got the app from the .dmg it ran perfectly, no errors what so ever. Then I tried to do the same thing with the one online, it raised the same error it had earlier. The only difference was from where I downloaded it. If anyone else has the same problem they should try downloading Tilemancer from the itch.io app and it might avoid the error.