Having looked over your figures, I'd suggest moving to sweeps immediately.
The offers you're currently promoting aren't working effectively enough that you can go straight into scaling/profit, and if you can't find new offers, that'll kill this entire approach stone-dead. -70% ROI from initial test with no optimisation is not unpromising, but it's not stellar either. The lack of new offers is a serious concern: normally you have to mill through a lot of offers to find success, and if you can't do that, you need a killer offer from the get-go.
You've clearly learned a lot: if you move straight to a much larger vertical you'll have a good chance to achieve success fairly fast.
Alternatively, you could move into testing more general mobile content offers. That's a huge vertical again, and you'll have a good chance to achieve success there. But if you just stick in the narrow gamestore area, you're likely to hit issues that will slow your progress.
I've also re-tagged your post as a Follow-Along.
Good luck, and looking forward to your next results!
Caurmen, I truly appreciate your input. I'm going to revamp my strategy tonight and tomorrow, and comment back here with my updated strategy + action items. Thank you so much!!!