The university instructor Professor Avish has been asked to give an important lecture, and was invited to stay in a hotel the night before. When he woke up in the morning, while still in his pajamas, he discovered to his amazement that he is not in the hotel, but in a mysterious castle with many rooms. Eventually the professor was able to escape from the castle and make it to the lecture. He then decided to change the original subject and instead narrated to the audience what happened to him in the castle. He has taken pictures of every room, but unfortunately forgot how he managed to get out of any of them, so that remains for the player to figure out.

Avish! is an Israeli-made puzzle game with action and platforming elements. Each room in the the castle is built like a puzzle area, and the player's goal is to leave it, proceeding to the next one. The professor must avoid obstructions in order to find the key that will open the door to lead him out of the room.