I think retro as a term still has meaning but it differs entirely between people and within certain contexts.
To me, a game that is retro is one that has a 16 bit or earlier art style, so Hotline Miami has a retro art style but a game like Skullgirls or the original Binding of Issac does not.
However, Binding of Issac has a retro gameplay style, it is basically original Legend of Zelda in gameplay with new variables added in. The "New Super Mario Bros" games are retro in design, while having 3D graphics, they use the old 2D side-scroller design that they started with.
And to me, 1 on 1 competitive fighters are never retro in gameplay because while graphics and other things have improved, the general gameplay has remained the same.
As I wrote this I think I came up with a workable definition for retro, at least vaguely. Retro defines something that is a sort of thing that is not the current high-tech design. My wording needs a little work but basically 16 bit style graphics have been replaced with full 3D graphics in most cases, so that older art style is retro because it doesn't conform to the current technology. Same goes for gameplay, Binding of Issac is retro in gameplay because while it uses essentially the same controls as Legend of Zelda did, other things aren't retro like the game's random generation of levels and powerups.
I think fighting games sort of suit this definition the best, in that from the gameplay standpoint, fighting games do not have any real retro equivalent. While each game has different controls and inputs and mechanics, they all work essentially the same way that Street Fighter 2 and the old Mortal Kombats did. If Super Smash Brother's gameplay style had taken off and been replicated successfully, then you might be able to argue that traditional 1 v 1 fighters are retro in comparison to SSB but SSB seems to be the only game that managed to be popular with that sort of gameplay. It is less of an improvement and more of simply an alternative.
I feel Doom and Duke Nukem 3D are retro FPS games because while they are great, they are inherently outdated. I like the sprite-based enemies in those games but I wouldn't argue that the sprite based enemies are in anyway superior to the modern 3D models in FPS games today. Some people might and therein lies the problem, retro has different meanings to other people.
To me, a game that is retro is one that has a 16 bit or earlier art style, so Hotline Miami has a retro art style but a game like Skullgirls or the original Binding of Issac does not.
However, Binding of Issac has a retro gameplay style, it is basically original Legend of Zelda in gameplay with new variables added in. The "New Super Mario Bros" games are retro in design, while having 3D graphics, they use the old 2D side-scroller design that they started with.
And to me, 1 on 1 competitive fighters are never retro in gameplay because while graphics and other things have improved, the general gameplay has remained the same.
As I wrote this I think I came up with a workable definition for retro, at least vaguely. Retro defines something that is a sort of thing that is not the current high-tech design. My wording needs a little work but basically 16 bit style graphics have been replaced with full 3D graphics in most cases, so that older art style is retro because it doesn't conform to the current technology. Same goes for gameplay, Binding of Issac is retro in gameplay because while it uses essentially the same controls as Legend of Zelda did, other things aren't retro like the game's random generation of levels and powerups.
I think fighting games sort of suit this definition the best, in that from the gameplay standpoint, fighting games do not have any real retro equivalent. While each game has different controls and inputs and mechanics, they all work essentially the same way that Street Fighter 2 and the old Mortal Kombats did. If Super Smash Brother's gameplay style had taken off and been replicated successfully, then you might be able to argue that traditional 1 v 1 fighters are retro in comparison to SSB but SSB seems to be the only game that managed to be popular with that sort of gameplay. It is less of an improvement and more of simply an alternative.
I feel Doom and Duke Nukem 3D are retro FPS games because while they are great, they are inherently outdated. I like the sprite-based enemies in those games but I wouldn't argue that the sprite based enemies are in anyway superior to the modern 3D models in FPS games today. Some people might and therein lies the problem, retro has different meanings to other people.