Wow, so intense! I appreciated the difficulty tuning, it was very engaging. Overall just a really good, cohesive game. Leaderboard was cool, got second place. :-)
A couple very minor critiques. The next wave doesn't start even if the current wave is already completed, so maybe some people would like a button to skip the timer. And sometimes I would try to go back to the real world from the underworld because the temples were under attack, but clicking the real world button wouldn't work so I would have to keep trying to click it. Not sure if that was caused by some spirits being too close to the button or what.