Last call for #14, and I should probably start hinting into the TOP 10.

#14
Deep in the labyrinth is a ... waterfall?
Combine materials gained from slaying monsters to get magical stones.
This turn-based RPG is a spinoff of one of the classical RPG-series.

#13: Baldur's Gate guessed by The_Liquid_Laser

#12: Breath of the Wild guessed by The_Liquid_Laser

#11: Star Wars: Dark Forces guessed by The_Liquid_Laser

#10: Star Wars: Dark Forces guessed by The_Liquid_Laser
On the first day man was granted a soul and with it clarity.

Metroid Prime?

Have never played it, one of my gaming sins, so not sure about the wall of text.

Second Hints:

#15: A lesser known game that's similar to a big (unrelated) turn-based strategy series that's actually featured a couple times on my list, but then based on a very European comic. Guessed by Mnementh - Astérix

#14: Pretty much every hint one could give immediately gives it away; I just have to name one of the many corny one-liners and there's probably a meme out there somewhere.

Hint 2: Like the most famous one that has something to do with barrels and rolls. Guessed by drbunnig - Lylatwars

#13: If you complete a level 100%, you'll get sent to a heavenly place, where every hero there will scold you for not really being the hero the legend remembers.

Hint 2: Though heavenly; it’s a hall, not like a realm of clouds, but anyway, at least they give you weapons to use, most of the time, of which some are basically mandatory.

#12: Beachballs on beams in the sky grabbing keys, pretty weird if you thing about it. Guessed by drbunnig - Kula World

#11: Big heads and Elvis Presley.

Hint 2: But those are easy to cure, the epidemics are the worst. Guessed by drbunnig - Theme Hospital

14 - Star Fox 64 / Lylat Wars?

11 - that's got to be Theme Hospital.

And onwards goes the hint train:

10) The MC has taken up a bunch of new sports in this game.

Climbing, snowboarding, paragliding.

9) Sif, Zacian, the trope of blade wielding dogs seems to repeat.

8) Counting is hard... what number comes before 3?

Breath of the Wild

There it is!

Both correct! You’re climbing the ranks.

A game which I don't often see featured as a classic great game, although it really is. This Wizardry spinoff is one the greatest RPGs of all time. It's battle system is classic but works well. The scenario and story are interesting and dark, the design of enemies is inventive and it has nicely implemented characters. The game has stellar level-design, something I see often for Atlus games. This whole package is pretty great.

Tale of the Forsaken Land is a dungeon crawler. You create your character quite freely and then go hire more people to form a party to start exploring the labyrinth. The story background is the kingdom of Duhan, which is pretty destroyed as an event called the Flash struck the land. Now a dangerous labyrinth exists within the ruins with lots of monsters. The labyrinth has parts of the former kingdom of Duhan, that are now through the events rearranged and becoming part of the dangerous landscape. You set off with your party to explore the labyrinth and discover the reasons for the recent events.

Although there can be humorous moments, the overall tone of the game is pretty dark. This is expressed by colors, music, the quests you get from the people in the Inn and how the story unfolds.

The fighting system is quite classic, but has some twists with the allied actions. In the labyrinth you have additional things to do, like open new paths or unlock trapped treasure chests.

This game is a pretty gem, clearly underrated.

https://www.youtube.com/watch?v=AvWkzFNTBo0

14.  Wizardry: Tale of the Forsaken Land (am posting this and see that you posted it just before me).
10.  Demon's Souls?