A bit offtopic, but considering your approach, do you use a game engine ala Unity to create your games as fast as possible or do you create your own little engine?
But the answer is use an engine.
I used to both buy the rights and lease the rights to tons of small games though and then release them on steam. They were all made in an engine(unity, rpgmaker, xna, etc)
It is never faster to rebuild the wheel.