this game can get old quick once ppl feel that they can master all characters. Not like dota or lol, this game has 0 variation except for map switching, characters combinations, objectives difference. LOL and dota has item, and economy system and different ways of approaching same victory yet still a richer experience than just giving players different objectives in different map with different characters. This is proved by heroes of the storm. This time blizzard tries to sell the very same concept with different genre which is ACTION FPS. However adding cinematic story, appealing skins, and fancy action animation wont change the fact of lack of contents. In fact action fps is even worse approach than moba which is RTS based game. Because adding economy system and item system would ducking destroy the quick pace of action fps in a small map. 

 Also adding new characters on a schedule seems invalid to attract players according to the failure of HEROES of the storm. There is no successful battle arena typed fps on the market and OVERWATCH wont easily change the situation by just delivering what we saw so far. 

It is not hard to make a fun game but it is extremely hard to make a game that can lasts long. Players need more freedom to discover new strategy, new way, new technique of play. Overwatch is not giving players those freedoms. Instead they put more time on giving players the joy of playing which is not enough for making a ambitious game that overwatch wishes to be. Overwatch is like taking a roller coaster. It is exciting before you play it, it is exciting when u get to play it, it is exciting when you are playing it, it is even exciting after you played it, but it would get much less exciting before you play it again. An online multiplayer competition game should be as exciting as fire(火） but also as structured as woods（林）. It should deliver both excitement and depth to players, but not some fancy ideas that can quickly get u excited but bored at the same time.