Really fun take on the wave survival concept, I love how frantic it quickly gets, as I desperately rush around trying to find the right element for the current wave. I will mention that I don't think the tower should block player projectiles, I think it messes with the flow too much, and the location of the mark pickup means that enemies can often block it which pretty much guarentees a loss. Still, I really enjoyed this game, and I'd love to see the concept expanded further.