Thanks friend, the game was actually completely broken. I've pushed and update and if you want you can give it another shot :)
Oh dear! I've just given it a replay now, much better! I understand the core gameplay loop now, however I may be experiencing another bug there I can't get past the second wave of enemies -- I'm stuck in my tower!I think there's still lots of potential here.
Thanks for giving it another shot. I'm glad that the concept seems fun, even in this early state.
