Some games have multiple endings. Some of those have "True Endings". Sometimes they are referred to as a secret ending.They are almost always the desired ending. Being longer, tying up loose ends, extra cutscenes are some of the benefits of getting the true ending. JRPG's for whatever reasons really seem to be the dominant force when it comes to true endings. Many times they involve some obscure set of invisible rules the player must complete in often times, a shocking display of randomness. Some games go so far as to not give you the true ending even if the player so much as does one thing out of order or answers a question wrong. Usually though its a complex affair. Many times the only way to be sure you are getting the true ending is to look it up which is inevitably filled with spoilers.
Valkyrie Profile has an ending that most information says is impossible to get by accident. You must have lowered Valkyries Seal Value by a specific number by a specific chapters. Complete a named tower by the end of chapter 4. Recruit two specific characters in chapter 3. Send a specific character to Valhalla in chapter 5 or 6. There is several guiders on how to achieve this ending. All contain massive spoilers and are extraordinarily comprehensive. About 45 hours to beat the game.
What are your thoughts on true endings?
I like true endings, so long as they follow and favour the most complete route / path of most development for the characters. So like with Valkyrie Profile; you have to unearth Lenneth's past, deal with Lezard and a whole bunch of other stuff I'm forgetting. You pretty much do all the things you only scratch the surface of in the B/C routes. True endings should both embody & conclude the main story's themes, I think.
I feel true ending/routes should also, where appropriate, favour / include said game's waifu (and that character's main quest / plot beats should lead up to and play into the finale. Not the absolute best example (and I can't fully cite the details as I've yet to do it), but something like Nyrissa in Pathfinder Kingmaker; she's one of the main baddies and plays a pivotal role in the story, but is also a hidden romance. Similarly, you could have characters like Morrigan in DA:O who tie into the endgame and the continuation of that arc in potential (properly made) sequel is obviously infinitely more interesting than the characters without a tie to the main overarching plotline. Another more contempory example might be Geralt's love interest in Witcher 3; it's very much set up to favour Yennefer, and in my opinion, rightly so.
Ideally, I think a true ending path should be somewhat hidden/obfuscated; while we can debate the execution, the recent Pathfinder Wrath has its true ending hints littered across the path of the game, but you'd probably never fully unlock it the first time through. This is fine, I think, like with Valkyrie Profile, having a riddle to ponder and having to read between the lines to find a hidden way of dealing with/escaping a seemingly inescapable situation strikes me as something that is an inherent positive in gaming. I think allowing the player a hidden, hard to achieve "out" or way to overcome a situation where the deck is stacked against them, and allowing them to feel that
they figured it out themselves is a great way to end a game (although, debatably, most game's true endings are too obfuscated, necessitating usage of a guide and diminishing any feeling of accomplishment in the process). I think Shadow of Destiny/Shadow of Memories on PS2 is a good example of how to do this well. In the game; you are killed near the start and given the ability to travel through time to some extent by a mysterious benefactor. Shit happens, and there are various ways the game can end, with the true ending being you getting the better of the antagonist. Admittedly it is a game meant for replays and structured around delving deeper until the player hits the true ending, but it embodies the notion of letting the player feel like they figured it out themself quite well.
You mention Lenneth's "Seal" value in Valkyrie Profile. I think there is probably enough to go on from the game's intro in the Weeping Lily Meadow and scattered across the game to guess at who Lenneth really is/was and to make a determination that the seal itself is something negative imposed on her by Odin. Sending specific characters to Valhalla in/by certain chapters seems a little more difficult to unravel imo. I'll grant you, VP's true ending path isn't perfect, but I think having it be somewhat obfuscated was the right call. Your first playthrough/maybe second - you can see there's something there beneath the surface, even if you don't know exactly how to get at it. Heck, I'm currently replaying FF7 (with mods) and there are moments where the game flat out doesn't tell you where to go next on the main plot path, requiring you to venture out into the world and gather info; unheard of in today's AAA space, but back in the PS1 days, not all that uncommon, I sure as heck didn't remember the game doing that till I started my replay a week ago though!
I think true endings, if they are picked as canon by a developer, offer an opportunity to inherit the most complex & payoff rich worldstate for a sequel, provided the setup was there in the first place. This in itself, I think, is often preferable to having 3 different flavours of "sweet fuck all" afforded to us in sequels with save imports. I don't give a fuck who my character romanced in game X if none of it matters moving forward, but is one of them becomes the Omega Doom Goddess 5000 in the sequel, sign me the fuck up, I'm coming in for that later payoff.
True endings can lead to one "gaming the system" I suppose, Suikoden being a good example, there are certainly some characters that probably deserve to die, but you
must recruit them to realise the true ending... I think getting the player to the true end finishing line, without it feeling "gamey" in some way, can be a challenge.
The Suikodens handled their true endings well in terms of final payoff, Suiko 3 particularly, given you got to see the antagonist's motivations and actions from his POV, with minor allusions to the Suiko 1 & 2 heroes true runebearers as semi justifications of his actions. It's one of the best examples of multi-game payoff in my opinion.
Shadow Hearts was an odd one, I think SH2 went with the bad ending, BUT, I think it ended in such a way that the SH1 good ending happens as a direct result of the endgame time travel shenanigans in SH2. As a result, both endings are "true" in a sense. My memory is hazy on this one though as it's been a long time.
Then you have endings like FFX-2's which arguably undermines the ending of the original...
Hell, despite my best efforts, I never got to see Vandal Hearts 2's true ending as the protagonist's waifu Rosa killed herself close to end due to me missing something... twice!
Then there are games where you can't get the true ending on your first run, but it's still the true ending, even though it's initially unachievable... This seems a bit illogical, but there's games that do it.
So in conclusion, I like them, they shouldn't take the form of a 100% collectathon like FFX-2, but should instead require a series of actions from the player to unlock.