Yeah I agree, the intention was for the robot to merge with the robot friends, but we couldn't get it to work in time. I think I may try to remake this at a later date with my original vision solo dev style.
A simple time friendly trick would be to just "brute force" it, by creating pre-made sprites with the possible combinations. check which parts you have picked up and then load the proper sprite.
If you have a lot of time, you could write a procedural sprite system in which each component could be swapped out.
Keep up the good work.