Happy 2017! We've released a small bug fix patch for Rogue Continuum, fixing the bug where you couldn't level up your hero past Level 15 (somehow in a previous patch we had messed that part up). Anyway, everything is fixed now and ready to go. Thanks to everyone that pointed that out to us. Now, we should all be able to hit level 18, which is when the ultimate abilities for the heroes unlock. Fyi, after level 18, there are no new abilities to unlock - from there on it's just stats and skill upgrades, until you hit the final max level of level 25.
Cheers, and we hope everyone is having fun saving earth again!