A concept that made it to demo stage, but was probably never meant to go into production.

Video Game artist veteran, Paul Reeves, has made the following quote about Birdie.

Myself and the other 5 Micro Machine 64 team members, 2 artists and 4 coders, for our following project, developed a small batch of concept designs; two of these actually involved playable demos. One being a crazy golf game called Birdie, and a futuristic Pong style game called, Jetball.

source: smoothdevil