I read somewhere that you would like te hear from someone who's has been playing this on a Mac. Well, I did, and I don't think there is anything technically wrong with it.
I did notice that you have just a few functions on the lower side of the game screen (history, skip and auto) while other renpy games usually have a whole row of functions. If that's a deliberate choice, okay. But I would suggest putting the 'safe' function back. (I know, right click also works)
For the game itself (searching for the right words, better just be direct and honest but on a friendly tone): it comes to me as a little bit of sloppy.
First: de tekst varies in size, especially in the prologuey. Looks sloppy/hasty.
Second: (I play desktop, windowed size) most of the game the whole screen is filled, but then a few scenes follow with black sides at top and bottom, resulting in a different screen size, while the tekst is displayed in the black. Looks also off key.
I see it's already mentioned, but in one scene not the whole tekst from the professor is readable, see attached.
Story-wise, nothing to do anymore with wat platform is used:
Personally I think you let the player jump into situations too unprepared without even a hint.
Starting with the basketball scene, while I do like the puzzle element, it took me a couple of times going back to find out what I was supposed to do.
Suddenly over to the scene in the back of the cart was okay, because slowly as a player you get explained why that was afterwards. But then suddenly the story jumps to other characters, in the tavern and at the professors lab. Maybe just a little frase "meanwhile, in the village" will do the trick, maybe it takes a little more effort to let the story feel more fluid. But in all, the story just jumps too much.
Last little thing, during the fight with the rats (easy enough for a first fight) in the second round an imp appears, while the professor starts warning about them for round three.
Okay, it seems I typed more than I planned to do. so I stop here. With just the last note that these comments are just my personal opinion. Take or leave what you want. Greetings.