Here are my ideas for the rivet...
1. Allowing the rivet to level up and change its shape with every upgrade.
2. Allowing the rivet to attack
3. Rivet can be turned off and on and while on it consumes fuel. ( so its not too OP )
4. Allow to equip shields and weapons with special abilities.
.5 The rivet should be able to die and should cost 100 C every time it dies, with the lvs and shields your pet should get stronger and after certain lvs you can buy abilities such as a repair feature for your pet over time.
These are just my thoughts about how this game could be improved. I have asked many people about this and they said they would love to see this. I know the rivet is only a vanity item but it could be so much more and should affect gameplay. If the rivet became like what I said above, it would bring endless fun and action instead of seeing a small little robot circle around you and occasionally break its cycle and go farther then it normally goes.. Please I beg u to make something like this, it doesn't even have to be the rivet. :)