In the answer he says 'used to play' means I played something in the past but not anymore, yet 'was used to playing' means a habitual activity but had changed some way.
For me, as a non-native English speaker, I feel these 2 sentences have exactly the same meaning because I played something in the past is a range of time. There could be an action that might be happened multiple times, not just only 1.
If someone has an experience in the past and wants to explain, nobody would say 'I had played the game' just a single time? Several retries could be happening within the range of the timeline. So I think this could be meaning a habitual activity too.
How native speakers do you guys understand these differences? What's the actual difference between used to play and was used to playing?