When I was 15 I decided to try and make a game in RPG maker (inspired by my then interest in another game that was made with RPG maker, Wadanohara). Needless to say I never finished it, but every now and then I'll get nostalgia for that time.

It came at a funny time because I was in between character creating "eras". When I was younger (11-13 or so) I would either make characters shallowly (just a "hi this character is named this and looks like this" without much story) or make characters that could engage with my friends characters, so the process was inherently collaborative (this project I talk about on my website is a big example of that).
Inversely, down the road after the failed RPG maker project (when I 17 and older), I found my footing of making my own characters and stories and whatnot.

So the failed RPG maker story feels odd. I have nostalgia for attempting to make it. I'd just painted my bedroom, and Super Smash Brothers for WiiU and 3DS came out (along with the debut of amiibos), so I have good memories of "training" my amiibo while the strong smell of paint waft through my room as I drew assets for the RPG on my highschool laptop.
That all feels nostalgic....But I feel veeeery little nostalgia (or even a fondness really) for the characters and story that I came up with. Oftentimes when I feel nostalgic, I express that feeling by drawing something related, but it doesn't work in this case because since I don't feel nostalgia for the work itself, so the nostalgia just sort of builds up in my body with no escape lol. Anyways:

Things that went wrong:

• Instead of spending my energy/focus on making the actual tangible story, I cared more about making the behind the scenes of it "clever". As if I was making only making a a trivia video explaining the behind the scenes of why something exists.
• I often included things in the story only because I thought people would like them, or because I figured it could garner some fanbase.
• Much of it was just me throwing traits/tropes I liked into a big bowl... regardless of how well they meshed with the other traits and tropes happening within the story

Many of these (all except maybe the second bullet point) could either have been ironed out had I had a more experienced hand, or would never have been a problem to begin with. They're less "unequivocally bad signs in a story" and more so "things I didn't know how to rectify/work with given the amount of experience I had".

If I had a fondness, I could rework the story/character elements I did come up with (because to be fair to my past self, there were some things there) but unfortunately for the story and characters - I don't. It all feels so empty.
Separately I was going through my 'if I'm never vulnerable, nothing can hurt me' teenaged moment, so it wouldn't surprise me at all if the emptiness comes from that. Writing that lacks vulnerability says nothing, and I don't think I allowed myself to be vulnerable even in writing fiction at that time.