Basically, Super Goof is Goofy but he has these power peanuts he keeps under his hat. When he eats them and strips down to his red long-johns he is, for all intents and purposes, Superdog! The stories are fun in the way PUREHEART THE POWERFUL is fun but they're played a little more straightforward.
At the same time, though, this IS still Goofy we're talking about so he still bumbles his way through most adventures with his cornpone optimism. If you've never read SUPER GOOF, check the dollar bins in YOUR comic shops! Starting there, you too might go on to discover the wonders of Carl Barks, Don Rosa, Paul Murray and Floyd Gottfredson!