Game Design: Openness and Player Choice

[Koh]

Yep, you pretty much nailed it.

No point for me to say much else.

Even in linear gameplay, this kind of stuff is indeed possible, it's all about the proper planning. And it definitely makes the game more enjoyable than when you have to wait on x to do y. One of the common things that makes me quit playing games is because there's only one real option in order to progress. There's no choosing your path, or how to achieve your goal, or even what to just not do. I actually quit in a lot of RPGs because the way it is laid-out is simply "you WILL beat this area, NOW, or get nowhere" Then when I have to grind and grind and grind to beat it, and even then, do not succeed, I quit.

In regards to difficulty balance with the converging point solution, it actually isn't made that much harder really.  You can balance the enemies in such a way that the enemies themselves are the level markers.  As in, while there's no actual Level-1, the enemies in the areas are setup so that newcomers can get the idea of what is Level-1 just by seeing how slightly stronger the next area's enemies are.  But skilled players are free to tackle them in any order, despite the stronger enemies, until they reach the converging point.
 
The converging points will know exactly what to expect the player to have in their arsenal, and for RPGs, should know their average level by the time they reach that point, and so things can be balanced with that data in mind.  Then when the path branches out again, the same approach is taken; the enemies are balanced with a hinted order, but there's no real order to actually do the separate paths, until the next converging point is reached, at which point the enemies are balanced without a shadow of a doubt relative to the expected player statistics.  This is shown in the first Zelda.  You can access all the levels right away.  And while you have to get the Raft from Level 3 to get to Level 4, need the ladder from Level 4 to actually finish Level 5, need the Recorder from level 5 to unlock Level 7 and any candle for Level 8, you can do those at any point.  The enemies, however, give you an idea how much later in the game that dungeon is hinted at being tackled.  but that doesn't stop players from going straight to Level 6 to grab the Wand early either.