That appears to be a complex matter. I had assumed it would be compatible with game engines, and I apologize for any misunderstanding. However, I will not be requesting a refund and will continue to support your endeavors.
Thank you. Technically, they (and every font out there) *is* compatible with game engines... just not "optimized" for them by default. They will all "work"... and for high res games they will be perfect! But at lower resolutions/pixel art games... it's better to manually edit for optimal results!