Personally I'm a big fan of how Your Shape: Fitness Evolved handled things. They also used a mirrored avatar, surrounded by buttons at arm's length. It was immediately obvious how to select something.
I still think hold to select is kind of a crutch, but I have no idea how to do things differently. Finger gestures will always come down to some arcane gesture you'll have to learn and pushing forward only really works for things that are right in front of you.
Your Shape has two ways of selecting an option. You can either hold to select, or push most buttons by moving your hand forward.