Yes, you can play Rocket League.
Yes, you can play Rocket League.
Yes, I played it with my Intel HD 4000 when I was waiting for my GTX 1060... though I played it at 1024x768 at lowest settings.... with about 80FPS. The iGPU was at its stock speeds, if you OC it you can definitely get quite a bit more performance out of it. I would expect at least 60FPS at medium/high 720p with your iGPU.