A couple of recommendations: If you’ll be connecting to sewer, and sewer elevation in the street is adequate, go with a 9 foot ceiling in the basement. Your half bath in the basement will cost less if you are directly under wet utilities on the main floor. Go with an oversized electrical panel (200 amp?) to make sure you have adequate power. Possibly an electrical sub panel for the Gameroom.
Where are you located? Other recommendations may be region specific...