Hey I think it would be great if the activity log didn't take up most of the screen for the main page of the dashboard. Personally I don't find the activity log particularly interesting or helpful and I'm not really interested in scrolling through it most of the time, since I have usually just done whatever is showing up there, so I already know what it's going to say. Maybe it could be on a separate page that you have to click to get to, or at least on a side panel so it doesn't take up so much space?
Then maybe the main part of the dashboard could show scrollable lists of quests, powerups and bad guys which you could just click right there to say you'd done them.
One problem with this might be that you can't see messages etc, but those could be dealt with in another way maybe.