Valve has released an optional, yet permanent patch for Germans who have had a censored version of Half-Life since its release.
In Germany's censored version of the game, there were no human enemies — only robots. The friendly scientists were allowed to be human, but shooting them resulted in an awkward dance of pain before they ultimate sat down for a nice, long timeout:
In Valve's words:
The full [uncensored] version of Half-Life is now available to users age 18+ in Germany.
If you already own Half-Life on Steam, activate Half-Life and start playing the uncensored version of the game right away.
The uncensored version will replace the edited version you currently own. You won't be able to go back to an edited version of the game.
Your saved progress won't change when you activate the uncensored version.
You can see the Steam page for the uncensored DLC as long as you're not logged in.
Or - and it's not like I expect many German nationals to be reading this, but - you could just go get Black Mesa, the mod that's been updating the Half-Life experience for years. It's decent, and not too long ago it finished the final area.