Is it a fantastic idea though? It's a simple mechanics that has been done to death since arcade machines in 70s and has appeared on mobile devices in tens of iterations.
Any Idea that makes $50,000 a day is a fantastic idea wheather intentionaly or not.
Graphics copied from Nintendo?
So what he's not been sued. He has taken the game down before even recieving a C&D.
Looks similar to other indie mobile games?
Boo hoo nobody is playing the other games they are playing Flappy Bird.
He is gaming the system and putting up fake reviews?
Bullshit. I haven't seen one shred of evidence that this is the case.
Its too simple / Not polished enough.
Sorry but these are the type of game the general public like to play. Sure there are other more mainstream titles on mobile like Xcom, Sims, Bards Tale, Infinity Blade or Epoch but, the big sellers that are played by the mass public are Candy Crush, Fruit Ninja, Doodle Jump, Angry Birds.
Look Flappy Bird has hurt nobody and the only people complaining are other developers who resent its success. I'm not even sure this guy even intended on it getting this big. I think hes is just a young kid learning to make games who decided to shove one of his experimental games on the app / play store only expecting to get a few downloads from friends and family.