Honestly at present I'd rather this game 3 stars, but I'm giving it 4 stars based on it's potential. A free to play game that uses Unreal Engine, plenty of unlockable characters and ultimate weaponry. Basic weapons and equipment can just be looted from enemies which cuts out a lot of the grind seen with destiny and warframe.
I see a lot of people complaining, saying the quests are monotonous and what not. I mean, this game that has only just been released is being compared to something like warframe, which has been out for god knows how many years - do you think warframe was always like it is now? I got warframe way after its first release and the content I have access to has more than tripled since then.
I think they've got a base for a really good game here, and as long as they plan to regularly update it and bring in new features and quests in the future, I don't see how you can go wrong with playing this. It's not like it costs you anything to own it.