Hello! Welcome to Feedback Quest 6! My name's Hythrain, and I'm one of the hosts and streamers for this event! This feedback is being written live on my stream.
This is a fun idea, but in practice it doesn't work all that well as is. Weapons work regardless of everything else, so if someone makes, say, a gun and that's it, it'll drop and just shoot everything and likely win. There should be a minimum number of pieces required, along with certain pieces required as well. Perhaps make it that the face is an "engine" of sorts and has to be part of the design no matter what, and the more faces you have the faster your machine goes.
Beyond this, there should be means to edit and delete bosses you made. Similarly, it should be possible to remove joints and pieces. Right now, if you make mistake then your only option is to reset entirely.
I see a lot of fun potential in this, but it needs some practical changes in order to get there.
Also, there should be a default weapon that every player has. Blocks and face don't really seem like weapons.