This game blows my mind and I actually stuck at most of the levels but I finally managed to clear the game lol.
The levels are well-designed and fun. It requires the player of both puzzle-solving skills and controlling skills which is very challenging.
I would suggest adding unique functionalities to the body parts (like the foot can help jump higher) to make them less useless lol.
I don't know if these are known bugs: (To avoid spoiler, I will just draw it out)
- A machine part may fall very quickly and penetrate the ground (causing it to disappear) when another machine part under it moves away.
- A chunk of machine parts just can't pass through some narrow space. Resetting the level may solve the issue.
Overall, very well done! Hope there will be a release version in the future!