As a game dev myself, I'd definitely love to hear more about the custom engine you used and why you chose it over the other options on the market (like Unity, which you mentioned).
It's the same engine as our much larger game, Planetary Annihilation. http://www.uberent.com/pa/ PA needs it's own engine as no off the shelf option is sufficient for it's needs.
Outland Games is a much simpler game, but the PA engine is modular enough that we could scale down to mobile. The upside is that a lot of the work for Outland Games will carry forward with the engine and help future projects (including PA).
As a game dev myself, I'd definitely love to hear more about the custom engine you used and why you chose it over the other options on the market (like Unity, which you mentioned).