Fighting games practically thrive on re-releases. For a genre so focused on systems, re-releasing the game every so often with seemingly minor tweaks to the roster with a few extra mechanics might not seem like much, but those changes go a long way. On the surface, these character changes might seem minimal. However, this is not the case, especially if one compares Sagat from vanilla Street Fighter IV to Ultra Street Fighter IV. Implementing old versions of characters, as well as allowing players to choose from a variety of preferred mechanics (the Groove Select option in Capcom vs SNK 2 for example), offers a wider variety of gameplay options, whether there's any strategic value to it or it's just for laughs. In addition to eliminating any need to keep playing older versions of that game, it also opens up a wide number of possibilities for competitive play, which is always welcome.