Average of all the games.

Kingdom Hearts Final Mix = 9/10
Kingdom Hearts Re: Chain of Memories = 7/10
Kingdom Hearts 358/2 days = 6/10
Kingdom Hearts 2 Final Mix = 10/10
Kingdom Hearts Birth by Sleep Final Mix = 9/10
Kingdom Hearts Re: Coded = 4/10
Kingdom Hearts Dream Drop Distance = 8/10
Kingdom Hearts 0.2 = 7/10
Kingdom Hearts X Back Cover = 7/10
Kingdom Hearts 3 = 10/10

Total = 77/10 which I will round up to 8/10. Bundle's very worth it.