You know in Hood Safari on the replays that things move faster using railgun, grenade launcher and rpg. You can also snipe MC Clip on both first play and replay, as long as you do it from the top of the hill.
I always get side tracked so hard that I can't focus on the story missions. It's both good and bad, I really want to complete the story. I only play solo mode because I'm 51 and just sort of an average gamer, online too competitive for me. But I enjoy the casual playing.