The Battle of Langnes was the last battle of the Norway swedish war of 1814. The battle ended in a stalemate with the Norwegian army able to retreat in good order across the Langnes River. This showed that the war was going to go on far longer then Sweden was particularly prepared for (they were especially worried about foreign interference). This lead to Norway haveing its own separate government and constitution (along with being seen as a sovereign state).
Frankly consdering the state of tge Norwegian army at this point in the war I don't think it would have taken much to create a desisive defeat during this battle, and completely destroying the army probably would be necessary inorder to render it combat incapable.
So what would have happened if Sweden had been able to force a unconditional defeat on Norway during the 1814 war. Leading probably to no sparet Norwegian parliament or institutions. How would that effect the Norway-swedish union over the course of the 19th century. Would Norway even be able to separate form Sweden by 1905 without the separate institutions that lead it then?