Quadrax

The Good
It's in the headline. First and foremost, the game is about puzzles and they are great, well-designed, well-thought.

You have 2-characters which have to cooperate to finish levels. You switch between characters and carefully choose what your next step will be. You can easily end-up in dead-end (so you have to restart level). Game is hard, but not impossible and finishing tougher levels is rewarding. The game gradualy adds new puzzle elements in later levels. Switches, elevators, teleports, different type of blocks (falling, exploding, non-movable, etc..)

Graphics is nice pixel art, but as I noted, release is 1996, so this is definitely not state of the art graphics given year of release, but this is not hurting the game at all as gameplay and puzzles are game's main point.

The Bad
Sound is almost non-existent. Intro animation / story is there just to have some story / intro, nothing to write home about. And game is loooong and hard.

The Bottom Line
Great puzzle game, and I dare to say, it's casual game. This is not type of game, you want to play from start to finish. More likely, you finish some levels, then you will take break from it after few days. Then return back and finish another set of levels. I guess only puzzle game enthusiast will finish whole game (in my playthrough some years ago I was able to reach around level 50, I was still far from the end of the game). AFAIK, it's for free now, running it in Dosbox should be cakewalk, so all puzzle lovers have great option in this game.