Inline

I mean, technically it's not a puzzle. It's just a simple inline-4 oriented upwards.
But that's the only category I think anything like this will probably fit.

Awesome Mechanism !! A very cool idea! The piston system is well thought out and very stable! This is great. Well done!
But the gameplay is very simple, for this 4.

Nice design. Would make a soothing dynamic screensaver.

I do not know if I should rate this level because the truth is that it does not have much playability... but was fun to see

مکانیزم جالب و به خوبی طراحی شده اگر به ان یک گیم پلی اضافه کنید عالی خواهد شد

@Denis Nazin
If you noticed I have multiple rotators driving the entire mechanism because sometimes it will seize up (despite not actually seizing up) and the torque of one motor is not enough. So I used two, and for safety measures I added two more.

It is able to run for more than 30 minutes (without jamming up), which is quite a good record for me.

It's really really old. It's about 4 years until I decide to publish it.

Playability, well, because I don't know what to do. I mean, obviously the map isn't big enough for the bot to crawl around the crankshaft, so ...
But to get the bot to move from one piston to another isn't a total walk in the park, either.

Lastly. I like the fact that people are actually enjoying it.