I am with sandytf, more context would be helpful.
If it is more "This is where we part ways my friend. From here I go alone." then it would sound very odd to use a phrase like "this is the edge of the level, go no further".
For the former something like "you're done" works well, though be careful with that as such a phrase is not uncommon if you are firing someone/stopping them so you can take over and may not be that friendly, unless the person is about the sacrifice themselves and in that case it is somewhat less aggressive.
For the latter would something like "return to the mission" do?
Until we have context though it is not going to do much good and you can look at end in a thesaurus as well as any of us.