Coming from playing mostly single-player console games where action-based games tend to be designed according to the number of buttons available on the controller, the sheer number of skills that you have here (and are expected to use at all times) is still bizarre to me.

You don't *need* thirty buttons to press to make a game interesting and complex. It can come from the challenge of the fight itself, doing the mechanics properly, reacting well, etc.

Or complexity of skills is added in ways that don't require extra buttons. eg. the Ratchet & Clank series, where you have a huge number of situational weapons, and will use multiple types in one fight, but at any one time you basically have Jump, Shoot, Melee and Change Weapon buttons. No weaving in extra skills, just shoot things and try not to let them shoot you. And it's fun and sometimes quite challenging.

Also, melee combos - normally you just have one button, and the combo simply happens on its own, as long as you actually hit the thing three times in a row. Three buttons are not necessary to make it "interesting".