Its funny that you mention mainstream/casual. For me mainstream games are games like Call of Duty most people would kill me for saying call of duty is casual.
For me there is gameplay wise no difference between lets say Wii Sports and Call of Duty. The singleplayer in COD is way to easy and the game itself is no challenge the other players you meet online are.
Wii Sports lacks online functionality but with some luck and time you will always find people that will beat your ass when you invide them to your living room.
The whole casual/hardcore debate is nonsense since former hardcore games magically turned into casual games.
Its more about accessible games VS unaccessible games (that need 15 min tutorials with tons of text to even explain the simplest things)
And then there is mainstream which are games like COD etc. Games that can be compared to mainstream movies like Transformers. They are okay not great and their biggest selling point is sensory overload Graphics/sound/BOOOOOOM etc...
And sadly we are already punished with way too many mainstream games and yes it will become even more annoying because studios with "rising" development costs will not risk to fail so they will go mainstream and the gameplay will suffer.
Thats why so many people feel that there is only a handful of developers making "real" games and that indie games are fresh etc.
The industry f*cked up itself and we can just pray that it will drop all the short term profit mentality etc...
