How did the multiplayer work in original DKCountry?

So, I've been playing some DK country returns, and saw a video that commented it was the first to have co-op multiplayer, which confused me because I swear as a kid me and my mom would play DK Country together on the good ol' SNES(Console of the year all years!) I'd go check it, but unfortunately our SNES has been packed up already since we're getting ready to move in a couple of months.