[Game] Rename `returns` to `rewards`

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (18de9a8) 88.46% compared to head (830e96f) 88.46%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1161 +/- ## ======================================= Coverage 88.46% 88.46% ======================================= Files 64 64 Lines 5947 5947 ======================================= Hits 5261 5261 Misses 686 686 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.