@PHaE, I have gotten a 50 combo on snails catching. And my brother has gotten a 30 combo on Whack-A-Seal. I know what you mean about them disappearing fast, or the snails dropping two at the same time. I thought the same as you at first, but you need to just keep playing the mini-game until you just do it. The snails are like randomly dropping, so if you KEEP playing, eventually it'll come at a good order for you to get the combo. Same for the seals.
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