Basically something that made the game itself stand out from most others like seeds of destiny leveling progression system being a minor example and perhaps size & weight class being an obvious for this site.
I did originally want to put this into game design discussion but i thought general discussion would be better since these would be mechanics people had run into in games before and may bot be that new to other players that aren’t worthy of note.
Anyway i’ll go first just to get the ball rolling by what i meaning by unique… I encountered a game called momsterous which was unfortunately an ABDL type of game (i don’t really like that stuff) however it had this unique story progression choice system around AR as it related to the main antagonist were they were a succubus but they fed off of wasted human potential i.e these peoples talents and capabilities but clearly not using them to there fullest degree and thus feeds on that wasted talent start making them younger as a result.
Not my best explanation by far but i thought this game with how unique it was dispite what it foucused on was quite unique itself to use such a choice system that would effect your character long term throughout the story.
For me it was first playing Chrono Trigger and realizing that everyone gained exp even if they weren’t in your party, meaning I can have a lot more fluidity in using whom I want at all times in a game. I’m sure other games have the same mechanic but coming from Breath of Fire and Final Fantasy it was such a welcomed sight since I didn’t have to worry about grinding.
Another thing was the personality crest in Breath of Fire 2, which is used to keep track of how your party members feel about you as well as the people you encounter. It really sold the creepy vibe on the Church Island when everyone lacked any emotion despite it being perhaps the most populated city you’ve seen so far.
Lastly is a sort of a double one, but I find both to be equally great, which are Rune Factory 3: Harvest Moon and Rune Factory Tides of Destiny. For the first one, I loved the farming mechanic compared to the other two games since it felt like actual farming, making a killing each season while using the sheer amount of withered grass to revitalize the soil (regrowing plants go brr) which made it so much fun (not like Rune Factory Frontier). While Tides of Destiny had that mineral island that made it so easy to get all of the material needed to upgrade your equipment as well as to sell it at a high price across the island. Even without the money glitch in the game, it was very easy to start snowballing into having so much money. Sigh… if only there was a way for it to be harvested instead of having to pick it up yourself.
Two worlds 2. The magic system was absolutely crazy. Who needs to think about shooting lightning bolts when you can chain a shotgun of low dmg rock pellets to summon 12 demons right infront of an enemy. Why invest in long cast times and mana requirements for a high tier mana shield when you can just protect yourself with an impervious tornado of barrels? Magic was truly outrageous in that game.
Probably Starseed Pilgrim, where you make your way upwards by growing plants and jumping up them, but then at some point space gets inverted and all the platforms you were on top of become tunnels you walk through.