I could answer this: SaGa 1 (aka Final Fantasy Legend 1).

Viewed objectively, there are many rather significant issues with the game:
* The battle system has many bugs in it. For example, when STR based attacks (the most basic type) are used, accuracy and evasion are reduced if you are not blind, having high AGI makes you take more damage from multi-hit attacks, the saw only works if attacker's STR < defender's DEF, and *many* other bugs of this sort. In other words, the battle system code is a glitchy mess. (It's remarkable that I have never seen the game crash, despite how poor and buggy the battle system code is.)
* The growth systems for Humans and Mutants lack any form of diminishing returns. Humans get stats faster as the game progresses, until you run up against the limit (or trigger integer overflow). Mutant stat growth is completely determined by the game's RNG; there's nothing you can do (sort of RNG manipulation) to control it.
* The RNG is awful; for example, it gives the same results after every power-on. It's bad enough that it hurts casual play (it's quite possible to have a Mutant with only 20 HP at the end of the game because of this). It also means that, if you load a save and then get unlucky in a boss fight and lose, when you try again, you will get unlucky *in the exact same way* and lose again. It's bad enough that RNG manipulation is something you may need to do in casual playthroughs.
* In multiple places, you can get into a place where you have to fight a boss in order to leave; if you are not able to kill the boss, and you save your game there, you are softlocked and have to start the entire game over. (I note that there is only one save slot, and no warning when you try to save in this state.) I suspect that you might be able to softlock yourself by dropping the ERASE99 item, though I am not sure about that (other important items can generally be retrieved where you found them if you drop them by accident).

And yet, I find the game rather fun, and have soloed it numerous times. Perhaps it's because the game is so short (for an RPG) and fast-paced; I wish more games would be like that.

(One more thing: In the second half of the game, the plot can be rather disturbing; not what you'd expect from a game from 1990.)

Anyway, perhaps I can say that the last question I asked still stands. Or, if you want, you could give a different answer to RedWolf9000's question, if you wish.

In spite of all its flaws I have a special place for Two Worlds. I really felt the game had potential. Unique mechanics like combining equipment was fun. Yet the horrible narrative, bad voice acting and mostly empty later portion of the game was a huge disappointment. Still some of the ideas in the game were good.

Q: How do you feel about sandbox style games?

They can be fun for playing around, but are not the best choice if you want a well-balanced challenge.

(Morrowind is the perfect example of this; it feels like, given the choice, the developers decided to allow the player to do fun things (like jumping over mountains) rather than attempt to keep the game balanced.)

For a challenge, a linear gane, or at least one which doesn't give you too much freedom (at least not right away), will likely be more balanced. An in-between approach can also work well, allowing for some creative routing decisions.

One other advantage to non-linearity is that, if one part of a game is too hard, the player can (at least temporarily) skip it and go somewhere else, coming back to it when either the player or the character is more prepared for it.

So, sandbox style games have their place, and they can be fun, but not every game should be a sandbox game.

(By the way, sometimes it can be fun to play around with the game mechanics and the AI; in unpatched Two Worlds, for example, it's possible to beat the game in a few minutes this way, as was demonstrated at SGDQ 2016.)

Q: Given the choice between two choices when building your character (or otherwise early in the game), one which will make the early to mid game easier, and the other which will make your character slightly more powerfulk in the long run, which choice do you take?