I haven't played Runescape for several years now.
My current game roster includes some noteworthy examples that provide exactly what you're talking about: an adventure.
1. Genshin Impact. Because of how this game is developed, they have large content updates once a year to introduce a large amount of new areas (a new continent, generally) filled with new NPCs, quests, puzzles, and the like. Understandably, this is hard to accomplish unless you have a pretty massive budget, which I am not certain Jagex can manage. (they also have smaller content updates to keep things fresh through the year, but it's more like temporary events like the Beach Party in Lumbridge)
2. Valheim. This game is procedurally generated and has a 3d destructible environment. That's already extremely different from Runescape, so it's hard to compare. But, Valheim has incredible sense of adventure as you continue to explore a very large world, and although teleportation exists, it's more limited than Runescape. Runescape allows you to teleport to within ~2 minutes of sprinting from anywhere in the whole world, once you've hit end game. That just kills any sense of adventure/exploration.
BUT, there is one very interesting lesson from Valheim: players have taken to challenging themselves to play WITHOUT portals or the map. This is similar to Ironman mode, except it does NOT remove interactions with other players, it just makes navigation much more challenging, requiring a lot more care. If they wanted to try to do something like this in Runescape, I would think it would fall flat unless it was in a procedurally-generated environment. But, the Sliske's Endgame maze is an indication that this might not really work at all in Runescape.
If Jagex ever makes an action RPG, I will definitely give it a try. I think they have a solid IP with good, likeable characters, and good story. I think they could make "Genshin Impact" Runescape style and it would be a very appealing game. But, quality matters.
15-Jul-2023 07:49:18