Meld

"Meld" is a parser game in which your character can >meld x with y, which combines two objects to form a third one, or >unmeld x, to create two objects from one.

The setting is a contemporary town with a few locations and characters; apparently melding is a sought-after capability in this world, and nobody objects to people doing it in plain view. However I felt that the story was kind of odd: an absolute stranger decides to test you, makes you (Spoiler - click to show)meld your ID card to get (Spoiler - click to show)the key to a park with a tavern full of gamblers. This lacked stakes for our character: why is she acting like that and not just going back home, why is she humoring the stranger who claims (Spoiler - click to show)to know something about your sister when he could have just Googled that? This is a bit naive, not really the attitude you have when meeting a mysterious stranger... Besides, why (Spoiler - click to show)does she even use her ID and risk losing it for a total stranger? why doesn't she unmeld the key and just go?

Mechanically, the game is based on this melding capability, but it's not really explained how this works. Actually, the game explains that it's totally unpredictable. (At first, I thought that it was (Spoiler - click to show)about plays on words, since ring + ID card = key, keyring, keycard... but it's not an Andrew Schultz game :)) Personally, I understand "unpredictable" as "here's a way to get random objects to solve puzzles that the author dumped in the game" and "you're going to have to try all the combinations to figure out what the author wanted of you", and when the game explained that there was (seemingly) no connection between input and output, I was disappointed and couldn't see how this could be fun; I don't want to guess the author's mind as a puzzle.
If you wanted to use this mechanic, you could make it really random, i.e. the result differs on each playthrough, and like, you say that objects have an "energy level" so that two objects of level 3 can be melded in a random object of level 4, and this becomes about resource management / roguelike-y and could be fun. That's kind of the only way I see to have an uncontrollable mechanism as the basis of your game and to make it fun.

The implementation is mostly good, even if there are a few bugs (Spoiler - click to show)(can't >unlock gate with key, jacob doesn't react to the ring...). If your game is based on a systematic mechanic, though, you have to be ready and expect emergent gameplay and players being smarter than you, and at least provide several possible solutions to the puzzles. I don't really know if "Meld" does that in the introduction (not that I could see I guess), but that's something to be expected for a full version of the game.

In short, "Meld" left me unconvinced, because its central mechanic is not very interesting for the player since it cannot be predicted; it seems like the player would spend their time trying all the possibilities to find what the author intended, which isn't fun. It'd be better if this mechanic had some kind of rules the player could then attempt to exploit freely and to the best of their ability.