I would honestly love it if you made a longer version of this game, I would definitely buy it. The concept from the start is fantastic (and what a good play on the 'summoning' theme too I might add) but each little new mechanic makes it even better!
I wish the mouse wasn't forced to be confined to the window, and I wish the window could be resized. But this was a jam game so I 100% can understand and overlook those little annoyances. I also probably could change that on my own if I wasn't afraid to go poking into the files.