Have you ever written online about your projects? This stuff is endlessly fascinating to me. And your suggestion about a webcam makes me think about a problem a client and I had a couple of years ago that was never solved. It would be a completely controlled visual environment, so an ESP-cam just be the ticket if he's still interested.

RFID tags in the heels of the bowling shoes, tied to the users account. Implant a reader in a spot by the lane - stomp to play!