Im at the max level and this game is pay-to-win. Game play (character progression) stalls in a big way if you aren't shelling out real cash to empower your characters. The massive power creep that comes with any game that is getting new characters regularly only make the P2W model more evident with each release. Free players will struggle to get even one full team of high powered characters while people with cash to burn can get even new characters to max stars with relative ease.