Warren obviously downplays his work after Gottlieb/Ratslime* because this talk is about Q*Bert but it's worth watching the documentary Insert Coin about the technology he was helping to develop at Williams/Bally/Midway in the years afterward.

https://www.youtube.com/watch?v=g1OXgCmOvbQ

The digitization of live actors wasn't completely novel but definitely helped accelerate a generation of iconic arcade titles in the 1990s.

(* I had heard the story about "Mylstar spelled backwards is Ratslym!" from others in the business and nobody could remember who it was but Warren admits it was him and that's awesome.)