Die Höhlenwelt Saga: Der Leuchtende Kristall

The Good
The game takes place in a fantastic world: an alien planet - a "hollow Earth", actually - its surface is uninhabitable due to the lack of a breathable atmosphere, but it's hollow inside and this inner part is home to a medieval-like humanoid society which has been enslaved by reptilian invaders since about a thousand years. This idea isn't perhaps very inventive - there's a lot of such plots in fantastic literature - but it creates a very nice contrast. The game's intro looks completely sci-fi and then, suddenly, after the protagonist makes his way through the cave labyrinth, which ends with a primitive airlock, suddenly he's in a strange new world inside, very different from the planet's surface...
When I first saw screenshots from this game, I thought this could be the most beautiful game ever made. While I'm no longer that intensely amazed, the graphics are certainly beautiful. Just the kind I like: hand-painted SVGA with a "fairy tale" feel. Of course, the contrast between the sci-fi beginning and the "medieval" world inside the Cave World creates even more opportunities for beautiful graphics. In the introduction and the actual game's beginning we see the interior of Eric's starship (the main room looks strange, too large, but the cargo hold, where the moon rover is kept, looks very interesting) and two sceneries from the planet's surface (a large planet with rings is visible nearby, so maybe this "planet" could be, in fact, technically not a planet, but a habitable moon, like, perhaps, Europa or Titan in our Solar System). Inside, we strangely see nothing that would indicate that we are inside a "hollow Earth" - the sky looks just like it would on the surface of a planet with an atmosphere. This world is dominated by steep mountains and has several towns and settlements - from Wiesen-Sulzthal, which just rests inside a valley, to Berg-Wolkenheim, which is high up, only accessible with a flying dragon, and has small houses "plastered" to the sides of high mountain peaks... Actually, we only visit one continent, or perhaps large island, known as Veldoor, and we get to hear about other places... Perhaps we would have ventured outside Veldoor if the sequel was actually made...

The Bad
While the graphics are amazing, at some point I started feeling a little disappointed with them. First: the number of individual areas visited is not so great. Second: a lot of interesting places consist of just a single room. Third: OK, the game has its animations (for example, once Eric tames a wild juvenile dragon, we can see animations of him flying the dragon over the map of Veldoor) - but scenery elements such as streams or waterfalls are non-animated. This looks unrealistic and definitely limits the game's "immersive" aspect.
Some aspects of the graphics are also inconsistent. For example, one of the paths in Wiesen-Sulzthal leads us to the bottom of a rock needle. Eric has to climb it once he buys necessary equipment. The base of the mountain is walkable, but already quite steep, it is dominated by purple-blue-gray shades, with small rocks resting under the vertical rock wall. And then, once Eric is climbing it... the colours are completely different, ochre-brown, and the base of the rock needle looks completely flat. Both sceneries are beautiful, but the little problem remains that they don't match.
The music is rather boring - exactly the kind which, to use a very graphic Polish saying in a literal translation, "falls in one ear and immediately falls out the other"...
The game relies very heavily on talking. The vast majority of trigger events are reached through conversations and it's usually very hard to guess it beforehand. For example, once Eric gets to Wiesen-Sulzthal with Hellami, some trigger events essential for continuing adventures (such as nuts on the tree ripening) won't happen until Eric chooses the correct conversation options so that Hellami leaves. (I was, by the way, disappointed that we don't meet her again in this game. I definitely liked her. A tough girl, for example in the scene where she pretends to be a soldier escorting a prisoner, and then tells Eric that he must follow her... and just dives into a mountain lake off the back of a large flying dragon...). These conversations are surely important and often interesting, they also let us learn more about the Cave World's history and lore. But they drag on for so long and there's so many of them that after some time it gets tiring... It just feels like too much emphasis on conversations and too little on other kinds of puzzles.
However, the most disappointing aspect of the game lies outside the game itself and probably not even fully the developers' fault. As the double title itself shows, the game was meant to be the first part of a slightly longer series, probably consisting of at least two parts. However, the sequel was never made - and, given that many years have passed, the game is relatively obscure (even in German-speaking countries, it seems) and its main author, Harald Evers, died in 2006, it's unlikely to ever be created. As the German Wikipedia says, Evers' way to become a "full value author" lead him through a "detour" into the world of computer gaming. While the sequel of this game was never made, the whole idea of the Cave World was developed further in a series of fantasy novels. And this series also remains unfinished, Evers died before he could finish it...
Still, even though this game may feel cut short simply because it is a part of an unfinished series, in many places it does seem somehow reduced anyway. For example, all these places consisting of just a single room, such as the temples... (Which, by itself, creates another annoying aspect: probably, given that the temples had no other rooms which could be opened later, the developers could have decided that the only solution was to make Eric discover some items later. Yes, but indeed, as other contributors have complained, "how am I supposed to know it?".) I don't know much about the history of this game, but I suspect it may have started as a very ambitious project, which would perhaps even present the whole story within one long game. The developers could have decided at some point that it's simply not feasible, that they have to divide it into more parts - with the first one culminating in finding the titular "shining crystal" ("der leuchtende Kristall") itself. If it was like this, it would explain these single rooms, relatively few places to visit, unused possibilities - the game could have indeed been "cut short" in the process of changing the project from one large game to the first part of a series...

The Bottom Line
So, altogether, "Die Höhlenwelt-Saga: der leuchtende Kristall" joins the unfortunate collection of games which just scream "Sequel!!" - but these sequels were never made. It also includes some famous games such as "Loom" - "Der leuchtende Kristall" is even more unfortunate in being quite obscure, only ever released in German and, it seems, not even being remembered by many players in Germany or Austria... For German speakers it's still worth trying, perhaps it may even become more accessible to others - I read somewhere about an idea of a fan-made English translation, though I have no idea if it will be made or if it will rather follow the fate of the sequel... But still, the game promises more than it actually delivers. The graphics are absolutely breathtaking, but later we discover that there are not so many places to visit, that they usually consist of just a few "rooms", and that the game relies too heavily on talking, which can make it boring, or maybe rather - just tiring - at some point. I really regret it because, perhaps if the developers had had more time and money at the beginning, it could have been a better game.