The End? is a medal.
It is unlocked after completing all campaign missions / completing Devs De La Muerte, the final mission for the first time. It is unlocked after the credits start rolling.
- Majority of players actually earned this medal on mission 39. This is because the original version of the game (v15) included only 39 missions. The rest was unlocked in later versions, but the game would still give the medal early until it was fixed in v20.8.
- The End? is also name of medals unlocked for finishing the campaign in SFH1 and SFH2.