Upon beating RE4, I unlocked some extra content which gave this near 20-hour game even more life.
The first bonus mode I played was Seperate Ways. This is Ada Wong's side of the story, and although the gameplay wasn't as fully fledged out as that of the main game's, it still made for an interesting game mode and it had plenty of story to boot.
I finished that last night, clocking in four and a half hours into it. This morning I played through Assignment Ada, which is basically a bonus mission for Ada. There were a few checkpoints, yet no save points, as it was mainly an extended mission, not a full story mode. Still, it was a nice distraction and pretty fun to play through.
I have yet to attempt Professional mode. That will follow soon enough. For now, it's on to The Mercenaries.