I recently got hooked on Twinkle Star Sprites, a Neo Geo versus shmup. Chaining enemies on your screen sends attacks to the opponent's screen. Those attacks can be bounced back, and reversing a reversal can create special attacks or even a boss summon. There's a lot going on and it's tragic that no spiritual successor ever tried to recreate this formula.
It did get a JP-only PS2 sequel, but it looks to just be largely the same game, just with a different cast of characters and the lovely spritework replaced with a much worse low poly 3D.