These minigames are for the beach event. They give out these Magical Pieces that give EXP/AP and even items if you combine them to tier 5. Instead of doing these annoying minigames, I have the packet structures (or created mods in instances where it makes more sense to do so) on how to tell the server you won the game without having to actually play it.
The following two games use the same OP: 0x661A
Byte: 1 // game type?
UInt: 75000 // total score
UInt: 20 // max combo
String: Stacky Cake
Byte: 2 // game type?
Byte: 10 // how many cakes you stacked
This a little more tricky, and I'm working on a separate mod for it. It'll be done soon once I get some more testing in (hopefully).
Edit: I couldn't figure out the packets to this, so no mod. However if you manually do a few successfully you'll still get a magic piece.
I've already got a mod for it here.
Natural Dye (gives a regular or metal dye ampoule of any color - no event reward)
I've also got a mod for this one as well here. However it can only be used once a day now (the first time this event came around it could be used an unlimited amount of times).
Puzzle Game (does not give a reward)
This one is super simple and super useless. Just send the OP 0xAB8A after opening the game.