I don't usually buy games like this, but I got it free with PCG and gave it a try. Now I really wish I had bought it!
Pid is an extremely enjoyable platformer, with great graphics to match. Each environment is very varied, and the requirements for some levels change too. My favorite example of this is in The Factory, which gives you several small puzzles one after the over, and is a nice break from the constant platforming.
The main mechanic, although basic, opens up some interesting platforming opportunities. And when combined with the numerous different items you find, there are a lot of ways to navigate around levels.
Sound design is also excellent, with the music fitting each area perfectly!
The game took me around 28 hours to beat on normal, but there are also numerous time trial challenges you can try, which are a nice addition and add to the replayability.
There is Co-op support, but i haven't tried this (I'm forever alone...) and so can't comment on it.
There are a few minor annoyances. Difficulty can fluctuate rather drastically at times, and it can get rather frustrating. Knowing where to go is also an issue at times. I only found the resistance's hideout
by accidentally pressing the interaction button while standing near the door. If it wasn't for that, i may have been searching for a lot longer.
But aside from these, Pid is a really good game. If you enjoy platformers, you'll enjoy this. If you don't enjoy platformers, try the demo and see!