I do see the humour in a mod sneakily changing my title
Doesn't. Even in the early betas sent to Let's Players before official release, there was artwork by Tiy in addition to Redigit's stuff. And of course, the music has always been by Resonance Array.
Hence why I said "if that counts". I know he did most of it himself (think it was everything but the sprites and music) and was the sole programmer until very recently. So in a way, it was made by a single person
Oh, there are a ton of great games made on old 8 bit computers and even the Amiga by a single person that I love. Out of them all it would be a toss up between Matrix (Attack of the Mutant Camels in the USA) for the Vic 20 by Jeff Minter and Poing 6 for the Amiga by Paul van der Valk. I have sunk countless days into both of those games. Once I'm in the zone with these games they become near zen experiences. Love them!
I miss the days of 1 man or small teams. Times where they could slap a $50 - $60 price tag on it after 3 weeks of developing and everyone with a share in the company became a millionaire. Now games have 50 - 100 - 300 man teams and the studios go bankrupt. I can see why the Bioshock studio wants to go smaller. Sell less copies, but everyone gets rich.
Soldat was made by one guy right? Michal marcinkowski? I think there's a bit of community effort involved with it, but I think its just him primarily. By far the best side scrolling shooter I've ever played.
But Carnevil does the WHOLE rest? Graphics? Level design? Engine? Game design? Mighty impressive if it's true.
I have no idea. I think other people have added things that have become official. Just like Minecraft. But I am not Carn. Someone will tell us :-) It is still impressive what Carn himself has done no matter how much or how little help he has received.
Space Engine, if you call that a game. I played it recently on a friend of mine's computer (that can actually run the damn thing and smoothly too) and it's amazing to me that just one man did all of this.
Hate to say it, but the only game I can really think of that was both definitively by one person (no-one else!) and that I really enjoyed is probably Cave Story. Everything else I can think of had some help somewhere down the line.
Braid? Hired an artist, used licensed music.
Dust: An Elysian Tail? Outsourced music and voice-acting (although said outsourced music talent includes Alexander Brandon, so this was definitely for the best).
Freedom Planet? Disregarding that it's not yet publicly released: music was being handled by another person from the start, the graphics were touched up by more-professional pixel artists, and the sound design was handled by the guy who animated Death Battle for a while. Not to mention, the whole thing's built on a Sonic fangame-community-made engine (even if the game isn't really a Sonic game at this point).
Maldita Castilla or Hydorah? Okay, so I've never actually played these myself so much as watch slowbeef play them repeatedly, but they looked fun. Regardless, the music was outsourced to a guy good with FM synth for that authentic arcade feel, so not one person.
Meanwhile, most other games definitively done by one person don't do a whole lot for me. I mean, Ken's Labyrinthlooks like it'd be a lot of fun (well, for as much as a Wolf 3D clone can be), but the lack of dedicated strafe keys kind of damper it a lot. (And that was with a source port. I should probably look to hack some in at some point...)
I will say that 2048 game is ridiculously addictive.