No idea if it will become "Live Service" or not. I can tell you if it becomes a pay to play/win, I will be the first one out. at any rate, the Beta is over and my impressions are...
The game play was quite fun to play. Some heros/villians seems a bit overpowered but I suspect there will be some buffing/nerfing before the official release. Nothing too drastic. Spiderman was the consensus overpowered hero. His web swing was so fast that it made it near impossible to target by the other players. With the right supports (i.e. Mantis, Hulk, or Rocket) Venom became the unstoppable tank with a slower 'web' swing. (Far more enjoyable for me to play)
@rainless To answer your question about The Hulk in a shooter game...
Edit- (Fandom link for The Hulk)
This isn't a true shooter game, though it certainly has aspects of them. Like many of the heros/villians, The Hulk has a unique play style with powers unique to him. He's the only character to feature three phases. You start out as Banner and have a little pea-shooter Gamma gun. You can "get Angry" when ever you choose to morph into The Hulk (note: you can not get calm and morph back to Banner...on you own). Once The Hulk takes form you become a Vangard and a melee tank beast. He features his signature Leap attack to get into position, his hand clap attack which they call his Gamma Burst and also does ranged damage, he also has a radioactive lockdown that stuns, and finally an indistructable guard which shields him and any close allies for a brief moment.
His Ultimate is to morph into Monster Hulk. In his final from he does incredible damage for a short time and is capable of grabbing opponents and destroying them (i.e. Avengers-Hulk vs. Loki).
Re-Edit- Once the hulk is reduced to zero health he morphs back to Banner and yu really need to get out of Dodge until the cooldown expires for you to get mad again. Banner is very squishy, as he should be.
Overall The Hulk was very enjoyable to play though very diffucult vs. some heroes that had the ability to fly like Ironman.