Well it took about 20 hours during our evenings, Wednesday to Saturday to put the whole thing together. I did all the coding and it was my first time back in Unity in a few years, so that didn't help. I'd say the main mechanics before tweaking and messing with art was around 5 hours.
Why do you ask?
Also, We put a few more hours into a patch that we're releasing tomorrow which really enhances the swinging gameplay (fully rotational player, rigidbody legs, some critical fixes that should actually make it playable on most machines).. if you enjoyed it (or didn't!) I hope you'll give that version a shot as it should've been that way initially.
Thanks for playing!