Fun is unpredictable. It ought to be straightforward to predict whether an activity will be fun, but it isn’t. The things suggested here might be fun, but there are no cast-iron guarantees. It’s a list of ideas: some cribbed from elsewhere; some adapted from their sources; some from my memory; others from my imagination. Some might tickle you, but not be quite what you want. Tweak them as you please! Elements might appeal, and send you in a new direction – that’s part of the process. Have fun!