Wow, super impressive game on display here! Hell, even if it wasn't a game, I'd already have to give this game massive props for the amount of charm through overall presentation: the game is a wonderous display of great, expressive and animated characters (like how Olive scribbles in her book when you're drawing, and how the lobbyman always has a new quip to deliver and keeps track of your stats) and just tons of little touches that give the world so much life and feedback to it.
The gameplay was a blast as well though, equal if not better than the charming presentation! I not only loved how fun and unique the concept of drawing attacks was, I liked how it also had a lot of good strategy to it, like the various enemies and their diverse attack patterns, and how you might think that using the square spell is always the best so you're shielded, but that ends up locking you out of your most powerful attack spell, the diamond: I love being rewarded for playing risky and aggressive like that! Top-notch stuff that I wouldn't expect from a game made for a jam, essentially!
If I was to have any complaints, there'd be the obvious big one: the image recognition logic used for the drawings. Now, as a programmer, I understand it's probably super hard to do something like this, and lord knows I wouldn't touch it with a ten-foot pole, so much props to you for even attempting something like this, as it is a secret genre I've always loved: drawing sigils and shit like that. But I found it disappointing that I couldn't draw freeform and had to use the strict outlines: bit of a shame as it made it so I always had to be focused on that side instead of the combat and felt so limited in expression to do shorthand or something like that (ironic for an artist, no?) Even accepting the outlines as the way to do it, though, I still had tons of problems where a circle would be treated as a triangle or a diamond, and that could be the difference between life and death, as I would be trying to do a cheap spell like circle instead of an expensive spell like diamond but not have enough mana, and it'd unfairly cancel it. Luckily the game is good and fun enough that I treat it as part of the challenge to get good instead of unfairness, but it's a tight rope that maybe some other people won't be as forgiving.
Other than that, there would some minor quibbles like I don't like how the intro cutscene and the tutorial proceeds at its own pace without waiting for my confirmation: I missed a lot of tutorial text on my first visit because I was experimenting and didn't notice the guy kept gabbing onward, and it's a pain that the only way I could see what I'd missed again would be to start all over and wait for that part to come up again.
Again, epic stuff on display here!