Yeah, the typical feedback is to make the rewards between rounds better as the rounds went on. Likely more time increase, more reveals added, and more copies of the cards being added as rounds go on.
The final round is actually round 10, so you were close. I was thinking most people would be losing on round 7-8 though. I could have stopped it at round 8 or 9, but I figured it would be better to let it keep going, and not accidenatly cut it short incase people could keep going.
I haven't beaten it, and most times I was also losing on round 9. I did get to round 10 and got through a good chunk of the matches in that round, although that was with some blessed rng and some dev knowledge. Some card packs are just inherently better than others, so knowing which ones to get and which ones to skip on and get other boosts helps.

