There were a few earlier Amiga titles that used the 4 player adapter facility, though my memory's a tad fuzzy as I only recall reading of them in some Zzap magazine reviews.
There use to be a popular adapter (I think) made by Microdeal(?) that these games used.
One was a shoot-em-up called Leatherneck,(or Leatherface??). I think Kick Off 2 also supported 4 players didn't it?
And there was also a couple of Tennis games that supported extra players.
One of them was by Ubisoft & the other by Loricel.
I don't have the magazines handy so I'll have to look them up later if noone can remember the names....