>>57348925I was originally going to mention the Regi sidequest in Hoenn, but cut it out because I was going over 2000 characters.
This is how Hoenn rewards exploration: with the Regis. Pokémon are the main attraction of a Pokémon game (duh), and so you get new and powerful Pokémon to catch if you explore everything Hoenn has to offer!
Sinnoh and Unova also have things like this, like e.g. Rotom in the Old Chateau (even though it's not a legendary), or the Swords of Justice in their respective rooms. But I think that Hoenn did it best: there's a long sidequest with puzzles to get to the Regis - and, if you don't explore during your main campaign, then you won't encounter where their chambers would be. All of them are hidden from the 'main path' and you won't see them unless you go looking for them.
Hoenn also has a bunch of “hidden places”, like the upper part of Route 115, the lower floor of Shoal Cave, etc.
Sinnoh has some stuff like this, like the part below cycling road in Route 206, for example. And I know that Unova also has extra routes and dungeons that don't appear from the main story, but the linear nature of the region does take away a bit from them.
>>57348961I'm a Kalos fan, though I don't say much about it because I hate yawnfag, and usually all of the criticism that's leveraged in good faith against XY is correct. I liked XY, but I just feel sad because, looking at the leaks, we definitely could've gotten much better games.