One of the 2016 REC Foundation online challenge entrants in the STEM Educational Video category provides an excellent framework for analyzing any new VEX Robotics game: VEX Robotics Guide to Effective Game Analysis. It's well worth the 3 minutes to watch (direct YouTube link).
Here's a summary of their methodology:
Appendix B, Skills Challenge: https://content.vexrobotics.com/docs/vrc-inthezone/VRC-InTheZone-AppendixB-RobotSkills-20170817.pdf
Game video: https://www.youtube.com/watch?v=1Yo_mlR1VJU