I switched in 2007, and until Proton came out I enjoyed 11 years of the finest Linux games, like OpenArena, Tux Racer, Oolite, Battle for Wesnoth, OpenTTD, and…that’s about it.
Lots of browsing Synaptic’s “games” category and reading package descriptions like “…is an engine that can be used to…”, “…game files can be created in…” and “…aimed at providing in the future…”