One late night I tried the PSP port of Mario 64 and I was greeted w "Itsa me!! Mario!!!!" First thing I do is turn the volume down, but I was already at the lowest volume. My only choices are "all of China knows you're here" or mute. The game itself also doesn't have any options other than stereo / mono / headset.

PSP port of Doom had the same issue. Fucking loud or mute. There are volume settings for music and sfx but changing them had no effect. I guess they're simply there as a leftover from the PC version, the modder who ported the game didn't bother to program them to work on the PSP. It's kind of interesting from a technical standpoint, in addition to being hilarious. That said, I swear I started Doom 1 from the select prompt but it was Doom 2 that booted up, so maybe the whole thing was just a fubar coded piece of shit and I shouldn't read too much into it.

Anyway I would pin it on them being homebrew but these are not isolated incidents. Gradually over time I would find that PSP games are really loud on the lowest volume setting. In fact I used to LIKE this about the PSP. "Hey, the game is the volume I want by default how convenient is that!" And it means I can quickly toggle between sound on/off for when I want to yell at my mom to make me hot pockets. When a game had volume that actually worked the way it should e.g. LittleBigPlanet PSP, I found it really strange and I somehow looked down on the game for it. Like you'd have to increase the volume meter to halfway to be able to hear the game. How laborious! And I can no longer mute the game on a whim when I want it! Whack!

I would imagine that this flaw of the PSP would "ruin" the system for me and the only reason it hasn't (thus far at least) is because so many games let you adjust music/sfx volume in the settings, thereby bailing out the system on an individual game basis. Come to think of it, after a certain point I probably began to use this feature in every single PSP game that offers it, without fail, often lowering the sfx to 40% if not lower (and often disabling music altogether) without ever really stopping to notice the fact of it. If not for the ability to do this, this flaw could very well have been the PSP's equivalent of the way the OLED Vita's minimum screen brightness is locked to Complete Ocular Destruction. At least with Vita there is a plugin that addresses the screen thing, but the PSP does not have one to fix the sound. At least, I don't think there is one.

tl;dr - I'm getting old and can't enjoy anything anymore