Since not everyone's computer could load OC itself or a scenario in just about 3 seconds, there would be enough time to read a few hints, especially for new players. These hints could be placed on the loading screen, and be displayed one at a time. I think new players, but also players who just updated and didn't read the whole list of changes since the last update, they would benefit from this. This could be simple hints like "Did you know, if you don't like your clonk's names, you can rename them in the player selection menu", but also things that are not that obvious, like "Did you know, you can swap items between your inventory slots by pressing both slot's numbers on your keyboard at the same time. Want to swap slot 1 and 2? Simply press 1 and 2 simultaneously!". If you haven't read it on the forums or in the repo changelist, you probably didn't notice this is possible.

Since not everything applies to every scenario, I would prefer having a file in the scenario or scenario folder available for this (like "HintsDE.txt" or "HintsUS.txt"). That would allow mods to have their own Did-you-knows and it would also not be too confusing for players if they play a modded scenario (i.e. Knüppeln or Boompack Shooting Ranch) and the hints simply don't apply to the scenario or they would apply to the original OpenClonk scenarios, but not to the mod (maybe because of modified controls or whatever).