The major differences in the Fishy Edition are:
The Fishy Edition does not require players to perform actions. Instead, whenever a player makes a pair, that player has to follow instructions – like draw a card, give a player a pair in play, etc.
Players only have to follow the instructions once for each pair (rather than for both cards in the pair).
The game ends when the first player gets rid of all the cards in his/her hand.
The player with the least amount of pairs after the game is over wins.
There is no difference between blue and orange cards except that orange cards are singletons that do not have a card that can be paired with them.