I'll be honest, I didn't quite finish it, I got about half way in one sitting, so take this review with a grain of salt. For a gamejam this looks and sounds very nice, enjoyable writing, enough options to be entertaining, but didn't wow me.
The art was very nicely done, however a few of the faces I felt were off, particularly Marisa. outside of the faces though it was well done and the artstyle was charming.
The VAs each did a pretty nice job, though as I lack familiarty with Touhou lore, I can't speak for how fitting they were. Only Hana surprised me, the rest fit characters as the script presented them.
Audio sounded nice, good quality and I liked the selections. the default settings made the occasional music a touch loud but they provide settings.
I'm not sure if M was meant to be a character fans would deduce, but to me they were handled in a mostly fun way, I wish they either used neutral pronouns or let you choose to be male/female as I'm not a fan of playing males in games, especially if they are meant to be myself.
If I may touch on the gameplay, there was one order where you're basically told "figure it out". you are given a clue that it should pair well with a particular thing, but no descriptions mention it at all, so unless you're already very familiar with drinks and/or the food in question, it's a blind guess between seemingly every drink in the game. I wish there was a bigger clue. Things like describing the food, or an offhand comment about what category or style of flavour would go a long way. "Any Simple drink will go well, but do you know which is best?" some line like that would make the choice less daunting.
All in all, a solid game that is impressive when you look at the time limit, but has a couple nitpicks.
P.S. I don't know if this is intentional, but you can scroll up through previous dialog and just redo choices. It feels like a bug but is a handy feature if you mess up.