Too Much Customization
Many people who know me already know that I have a thing against Capcom's Vs. series. Personally, the reason I see for them selling well is simply that people love crossovers, then the high-execution pros love the skill it takes to get the best combos involved. This is actually a good strategy in terms of sales, satisfying the core and the casual audience simultaneously. However, these games universally go too far and thus make what I consider to be flaws in their game design. Although my primary issue is the infinite combos they all have, my issue today has more to do with the level of customization they all have.