Hey really cool game! It drew my attention since it includes a bit of summoning like my game. Really well designed! I would love to see a more expanded version of something like this (I love watching AI type units fight each other).
Minor things is I think the game got a little bit easy if you rush money right away. 1st play I died round 3, but then second play I was overpowering all the knights and just stopped at wave 34 since with all my money I was so powerful! Also a tiny bit annoying with your guys spawning on either side, especially if opposite where the knight was going.
Overall though very cool! I liked it quite a bit! Good work!!