Light🐧⁂I got really badly burned by wanting to 100% complete Yakuza 2 on the PS2. The first Yakuza game on the PS2 had less side missions, was shorter and I really liked the pachi-slot machines were less realistic and the side missions with it where more doable with the help of a special talisman, while it still requiring some time and patience. In the second game the pachi-slot machines are a nightmare, they are more realistic wining the required amount is seems impossible.
There are other grievances I have with Yakuza 2 besides the pachi-slot machine where 10.000 medals needed under one sit, there are other mini-games that require the player to be good at mahjong, so I had to teach myself to play mahjong, now I can play mahjong and being somewhat an okay mahjong player. Now there's two side missions where the palyer have to play shogi, the first one "Shogi 2" is doable.
The second one "Shogi 1" is hard as hell requiring the player to be a really good shogi player or cheat using an shogi computer program along with an engine's AI which is a lot smarter than the game. I don't think I would want to do the cheating just to complete, especially because I still dosen't get 100% in the end, because of the darn pachi-slot machine and I don't mean "The Slot Ace" side mission that's doable.
Other very hard mini-games what is too much for me is the 20 of 20 home runs in "Alien League" in the Batting Cage and "Alien Curse" which requires 10 of 10 perfect hits in all difficulties to unlock. I'm not talking about the side mission "Alien Course" which requires only 8 out of 10 hit to complete. I had played both mini-games for hours and still can't be able to complete them.