Robot
Hi Ben.
I would probably make it on ARDUINO platform, just have experience with them and some of it's version are very small. In this way no need to bother with PCB design for a prototype, just ARDUINO PCB with some additions like button, buzzer, LED, may be an amplifier and 3D printed case with battery compartment.
I'm an electronic engineer with 7 years of experience in 3D modelling using SolidWorks. Good technical background.
Experience in 3D printing, manufacturing drawings.
I'm ready to discuss details by messaging before starting, contact me if interested.
Best Regards
Anatolii