Ok, I think I've got the skully rate figured out. The base rates per difficulty are: Easy 0.5/100mt., Normal 1/100mt., Hard 1.5/100mt., Nightmare 2/100mt.. These rates increase over time.
Can someone explain the rate of coin collection in Survival Mode? I've been trying to find ways to maximize it, but it seems erratic. I think it's based on 1coin/100mt., but this changes by the day. Fred's speed also seems to play a role but I'm not sure how yet. Also, does Running Fred have a wiki or other information site?
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