ChainDive (PS2)

Firstly, I'll apologise for the quality of the screenshots accompanying this post. PS2 screenshots never turn out perfectly, but the shots of this game are even worse than usual.
Anyway, ChainDive centres around a simple concept: your character has a lasso that can be used to swing

from the green dots littered around each stage. There are also enemies, who are defeated by first being frozen by your double-bladed weapon, and then smashed, by attaching the lasso to the frozen enemy and smashing into them.
The genius of the game is that it uses these small ingedients to make every stage different to the last. The first stage seems like a stage from any other mid-00s action game, with the added gimmick of the lasso: you travel from left to right defeating enemies on the way to the end of the stage. But the stages that follow are all totally different. A stage with no floor that has the player swinging from rooftop to rooftop, a stage with an incredibly high tower that must be climbed while fending off attacks, a stage exploring a cave to fin switches, and so on.
All these stages are a ton of fun to play, and the variety ensures that the game doesn't outstay its welcome. The big problem with the game in general though, is the difficulty level. Although the extreme difficulty does
result in a huge feeling of relief and satisfaction, it is still incredibly frustrating until the "trick" of each stage clicks in your head. And there are times when the game seems incredibly unfair, when you're desperately trying to find a dot to hook onto or when you fall into the abyss at the bottom of some stages with seemingly no way back up.
I still definitely recommend ChainDive to curious players, despite all that.