Hope doing detailed autism post is fine for the thread...
This game, Magical Block Carat, is the best puzzle game I've ever saw in terms of chaining/combo mechanics

. (And it's unfortunate that it's supposedly a porn game, even though the h parts are on a separate disc, because it makes it impossible to show it in public events/anicons.)
At its core the game is a match-3 (similar to panel de pon or Tetris Attack), but you have a button that switches the break to work either cardinally or diagonally at any time, including during combos

!
The game offers a ton, with customizable block sets (mahjong set!), mission mode that teaches you how to do weird shapes and combos, and killer soundrack on the pc98 version
https://www.youtube.com/watch?v=eman9Qg4m60
Will visit some friends for easter vacations, would appreciate recommendations for obscure games with local multiplayer if you have any!