Recs.
Updated
A puzzle game where the puzzles' goal are to reach the tetromino at the end. They have buttons, cubes, lasers and force fields similar to what you would find in Portal, as well as mechanics that interact with them (jammers, connectors). The game also has a philosophical story and backstory with optional lore terminals. The game is also divided into three worlds (and the Tower), each world into several levels, and each level into several puzzle rooms.
SpecsUpdate
Pros
Pro Great storyline
The puzzles in the game are great, but they're tied together with a thought provoking story line filled with mystery and intrigue. A story about a robot with human consciousness who is being guided by a disembodied voice, are they to be trusted? As the story progresses the player is drip fed clues which can lead them closer to the truth.
Pro Great original soundtrack
The soundtrack is very pleasant to listen to and fits perfectly with all the areas and themes present in the game. It varies from calm music, for those heavenly areas where you are solving puzzles, to more misterious and epic pieces for moments when things get... real. It's good to have some nice music playing while your brain is melting from solving the puzzles, or just appreciating the scenery.
Cons
Con Obtuse puzzles, especially with optional content
Mediocre game design all around. Many puzzles are ordered badly or redundant and could have been combined or removed to smoothen the experience, as well as occasionally not exercising the bounds of certain elements (like ranged pickup). The game's optional content is even more worrisome as it often leads you to play hidden object games to look in hundreds of corners instead of using more difficult puzzles. One particularly egregious example is when you have to interpret a message in a very specific way after using a decryption algorithm you may not know about into another questionable input system.
Recommendations
Comments
Flagged Pros + Cons
Con Ending troubles
After getting the "normal" ending you will have to replay the entire game again if you want to find everything you missed. Replaying a puzzle game isn't that fun when you already know the puzzles.