I watched highlights of a couple of games on YouTube. Only being able to rush 5 seems like an odd rule, but it's probably to promote more scoring. Only 2 point conversions adds an interesting dynamic to the scoring as well.
I don't have a problem with no kickoffs, as most kickers can kick the ball out of the endzone pretty much anytime they want to nowadays anyway. The onside kick being a 4th and 12 from your own 28 didn't come up in either of the games I watched, but it could be interesting.
The play was a little sloppy from the highlights I saw, but that's to be expected from new franchises. Obviously the talent is a little worse overall than the NFL, but the games seemed interesting enough. We will have to wait and see how it plays out to see if it has any long term viability.