I was really drawn in by the story and concept of this one. It has some cliches, but I'm not sure if we've seen a magical grandma in this jam before. I do wish there was a bit more background, but maybe that comes later in the game.
It's an odd mix of very stock RPG Maker feeling (the menus, battle mechanics) and very unique and custom (side scrolling adventure!). Overall it works well enough and is well presented, though. I really like the battle interface with the characters having different portraits as they get hit, run out of health etc. I think the character portraits in general are my favourite though I really like the overworld graphics too.
I'm not sure how useful a map screen is in a largely linear game; was it intended to be more open at one point?
In general I feel the battles are just a little bit too drawn out; the first two started to really drag about two thirds of the way through. It could get better later in the game, it could get worse, I didn't get there. I made it to the fight with the bats and kind of ended up in a hole where Cheryl went down and when I revived her, she was immediately taken down again by the bats. I like the idea of that battle, but waiting for eight bats to have their turn got old fast.
The abilities seem fine. I'm not really an expert on making awesome balanced battles. I really like Mia's improvised abilities, though I did find it odd that they're almost as effective as Cheryl's actual magic.
I don't really have time to slog through that battle right now, but I'm engaged enough by the story that I might come back to it post-jam.