Stanislav Costiuc, Farlands Design Den creator, talks about why Alto's Adventure has an amazingly beautiful narrative design and why Alto's Odyssey could not reach this high.
Stanislav begins by explaining that narrative design and a game's story are different things. Narrative design is about contextualizing the whole game including mechanics, the world, visuals, and everything else into something that makes sense holistically.
The game designer explains that Alto's Adventure is a perfect example of a beautifully done narrative design as the game does not really have a long complicated story in it (Alto's Adventure is an endless runner) yet you definitely get some elements of it that make the character's motivations clear. In the beginning, you see llamas, and as soon as you tap "start" they start running downhill. And here is when the main character starts his journey as he goes chasing the llamas.
Every element of the game makes perfect sense: the characters, the sceneries, the story itself. Herding llamas is what peoples of South America have been doing for many years, so the outfits, the names of the characters, the forests, and the mountains you see fit in organically considering what the game is about.
Alto's Odyssey, however, does not make much sense as it is not really clear why the character finds himself in a desert all of a sudden and why angry lemurs start chasing Alto. The motivation is nowhere to be found, the backstory remains an open question and the setting (though it is just as beautiful as the one in Alto's Adventure) seems to be a random choice.