3. Co-op
A great change of pace would be a co-op mode. Aside from how games are usually better with more players, Faith and her new partner could give each other boosts, assist in combat and split up to cover more ground. The time trials could also be played with two players, with both a competitive and cooperative mode of play to score the best times. Better yet, one player could take down an unaware opponent while the other speeds past and hits a switch, allowing players to hit a nice stride and do more in a shorter space of time. Co-op partners would also be handy for teaching new maneuvers and shortcuts to noobs like me, who just suck at everything Mirror's related.