Could OP (or anyone else who feels qualified, I guess) give me their opinion on a perpetual license as opposed to an annual license?

I have been considering building some licensed software and I had it in my head to offer an annual license to get at that recurring revenue, but...since it's client-only software (e.g. a game engine) that doesn't need to be making any API calls to my servers, I'm wondering if maybe that doesn't make any sense. I don't know...I've never made licensed software before and so I've never really thought about this. I guess I worry with a perpetual license that I'll run out of customers after enough people have got their hands on it. Maybe that's crazy, I don't know.

Also I would have no idea how to price a license...how did you arrive at your prices?