Zelda U (even though it's by far my most anticipated and I think it will be great, people seem to be hyping it a lot and seem to have unrealistic and varied expectations), No Man's Sky (incredibly hyped up because it looks so different and promising, but huge potential to disappoint and not live up to the promise of what some people expect because of that), Uncharted 4 (people will overhype it just because it is Naughty Dog).
Halo 5 will be recognised as a big game for Xbox but I don't think it will reach the level of hype in a gaming community like this as those other games. Mainstream media-wise though it could be overhyped.
On perhaps a smaller scale, Bloodborne, The Order 1886, The Witcher 3 and Star Fox U seem to have the potential to be overhyped. It's less about the quality of the games and more about which games reach hype / expectation levels that are just too high for any release to deserve them, and the games I listed are some of the ones I think could bring that out, along with a couple I suspect could be big disappointments even with the level of hype they have already got.







