The Nemesis system, where you get to create your hero's arch-enemy, may add something later, but it's currently a damp squib. You get the design tool at Level 25, but your control over anything other than your enemy's visual appearance and broad power-set (as in 'Fire' or 'Munitions', not 'Fireball' and 'Assault Rifle') is depressingly minimal.
The opening mission introducing your Nemesis is terrific, but the goodwill is quickly burned away by then repeatedly getting mugged by packs of your foe's generic minions while trying to go about your business. It's cool the first time, but gets old fast.
Champions Online is an unusual game. It's quite broken in many ways, but it quickly grows on you, and becomes surprisingly endearing. It doesn't always make itself easy to like, and it'll die on the vine unless it gets more areas to quest in and endgame content pretty damn soon, but it's a fun break from the normal MMORPG template, and even with its problems, worth checking out.
A conflicted superhero whose charisma papers over many of its personal issues. And you get to throw trucks at people.