But what if you REALLY try to do some work? And make MONEY? What if you have CUSTOMERS?
Summary: Jumping from one program (which you have worked for 2,5 years) to another, it is not economically feasible. It is actually a bad bet. It is done if you don't have any options anymore.
I'm seriously not trying to be confrontational, but objectively speaking, your two choices are to move to another solution that has what you need, or stay and hope that what you need will get developed in the future when the developer itself has stated no. If you're talking about betting, those options are like 100% chance and 0% chance to win, and you're saying the 100% is a bad bet.
The 2.5 years of development is already a sunk cost regardless of how you proceed. What you take away from it is up to you. Personally, I would say if I've spent years writing program worth publishing and I need to publish but currently can't, the fact that I've made it, I've seen it, and I'm confident in it, is still valuable to me (its called prototyping - one of the highly touted use cases for C2). I know I'll make my money back so I can justify licensing industry standard high end software to publish it (you have CUSTOMERS). I wouldn't care much about learning a new language, there are manuals and references for that. The game logic and structure are already all worked out, putting it back together in another program would be multitudes faster than the first time. Also, even if you have invest time to learn another program, regardless of the benefit for your current project, that experience will be extremely valuable for all your future projects since you seem to be quite serious about making money with this. In that endeavor, I wouldn't let my success be tied to any one program/company. THAT would be the real bad bet.