Spent an hour or two solving the delightful little puzzles. A progress indicator lets you know you're doing a good job unpacking the interesting magical mechanics, an ancient counting system, and a sneaky little beastie.
I held back from five stars for two reasons: I wish there were a bit more story or character to it, and I got stuck for twenty or thirty minutes on a parser issue. (I played back in the 90s, but maybe only one parser game since then... so I'm a touch rusty.)