A really nice game! However, I have encountered quite a few bugs. One common one is the game not changing from day to night, and clicking on "Begin Night" just gives money as if the night passed (but no monster spawned). This first happened when I completed the game. There's a lot of other small glitches, such as sometimes not being able to move buildings at all, or healers are turned into sorcerers automatically when starting a new game, or the circle animation at the beginning of the game looping annoyingly. But great job, keep it up! Are you planning on making the code open source?
Edit: forgot to mention I'm on Ubuntu.