Everyone expecting high sales just because Kojima is involved is really delusional. Kojima was developing Lunar Knights and (at least I think so) also Boktai for Nintendo handhelds, but those games were probably far away even from becoming gold. Only fanboys know that Kojima is the guy behind MGS, and even if some people would know that he developed their game, this doesn't mean they would buy this game now.
Gameplay-wise I can't judge, but since the latest 2D installments have been good I don't see much trouble either way, no matter if Kojima is involved or not.







