It would be fun!
Thanks, I'm a failed games dev' (at 4 I said I wanted to devise things for people, so my parents wanted me an engineer).
Unfortunately I don't think a Bionic Dues expansion would actually sell right now. The base game itself hasn't even broken even yet. :/
I remember the lauch was very bad: insulting Steam only (so I waited for a sale release elsewere), the screenshots were black and ugly and we didn't understand what happens in.
So, I finally bought in a sale on GOG, and discovered it's my prefered game of yours, even with its flaws (secondaries) and I play few now (but I always install it).