I keep thinking I ought to feel guilty about making a game that is, for the first time, unabashedly and 100% a fan game. Which isn't to say I haven't drawn heavy inspiration from other games before, but never so closely tied to a single game--
On the other hand, in spite of a few cosmetic changes the new project is, for all intents and purposes, Aerobiz. The design goals can be summed up as "I want to play Aerobiz online". Not "I want to reinvent Aerobiz" or "I want to remake Aerobiz"--I just want Aerobiz and nothing more.
Fan game or not, it feels pretty exhilirating. I mean, yeah, it feels great just to be working again at all after so long an absence. But it's amazing how much difference it makes to be working on a fully defined project--I've always thought I've done a good job of planning out games most of the way to completion before starting work, but the difference between working on a game that's "most of the way" defined and working on one that's fully defined is pretty amazing. It's just so much easier to work knowing exactly where you stand in terms of your progress--I've written up 80 to 90% of a game's planned features ahead of time, but I've never really noticed how much stress that last bit of uncertainty was adding. I think this explains a lot of the motivational problems I've had with previous projects.
Of course, then the difficulty becomes forcing myself to finalize that last 10% before I begin... I've always been a concrete, hands-on sort of developer, which has led to its own share of problems. It's just always been easiest to flesh ideas as I come to them, and now I find myself wondering if this is not the key reason I have so many broken and half-finished projects lying around...
Then I say to myself, "No, wait. I have so many unfinished projects because I am a lazy bum." Then I stroll away, whistling nonchalantly. (Or I would if I could whistle very well. Instead I mostly just hum, which isn't quite as nonchalant.)