It's very simple. Take your favorite PC game you've played in the last 5 years, drop ALL of the settings to low/off/whatever the least graphically intensive setting is, drop the resolution to half of your native res (or 50% scaling if available), and play it. See if you still enjoy it.
(for games with resolution scaling, bumping up to 60-70 can go a long way)
Report back how it went!