I haven't played a lot of IF since I was a kid, but I recently tried Counterfeit Monkey (https://ifdb.tads.org/viewgame?id=aearuuxv83plclpl https://ifdb.tads.or

I haven't played a lot of IF since I was a kid, but I recently tried Counterfeit Monkey (https://ifdb.tads.org/viewgame?id=aearuuxv83plclpl https://ifdb.tads.org/viewgame?id=aearuuxv83plclpl) and was blown away by the cleverness and depth of the system. It's many hours worth of adventure, and has a brilliant mechanic where you are in a world where real objects can be transformed by modifying their spelling (and, later, other linguistic tricks). So you might have a Can, but you need to drive far away, so you turn your Can into a Car with your Letter-changing Device. Or maybe you use your Homonym Machine to turn the wooden Bat in your hand to a Bat that flies around. The possibilities are endless, and the game has considered an amazing number of them. It's all set in a deep and realistic European island, with laws regarding linguistic manipulation, etc.