Had this conversation with some Vgchartz xbots users on what counts as an indie game. I said that an indie game are games that are made by an indepent studio and that studio owns the IP even if the game is published by other companies because many of the XBLA games werent published by the indie devs but i'd consider those games indies.

How would you define an indie game?

So a game like Spiderman would be an indie game?

If they're independent, then yes.

An indie can be a cheap solo game like Cave Story or a massive project like Witcher 3

No because it is developed under contract with Sony, who does have significant influence. And of course investors etc.  

Best way to put it is the development aspect is entirely under the direction of the studio.  Which means there can be investors mind and even publishers, but the studio is in control of the game conceptually and in the development phase.  

That's the key, the developer is in the driver's seat.  There's going to be some grey areas, but that's the basic.  Your game can be huge and ambitious like Star Citizen or small and fairly simple.  

So then it depends on how much control the independent developers have? A game like Sunset Overdrive Microsoft gave lots of freedom to insomniac. I'd consider that to be an indie game but would you?

I wouldn't because Insomniac was still dependent on MS's funding.

An indie game is a game developed by a self-funded video game developer.

An Indie game is any game developed without finding from a publisher.

Just because the dev studio falls under the same label as the publisher doesn't make it Indie. So a game like The Witcher 3 is NOT an indie game, it's what you call a AAA game.

Like I said, it is a bit grey.  I personally would probably not give it the indie tag given Microsoft did have considerable control over it.  I would sah 99% of the time when it's a contracted game, it's not going to be indie usually.  Honestly, the Witcher series is a more curious case.  The developer operates independent of publishers up until distribution.  So unless they have a large investment group or something over them, they are technically independent. 

And also, Indie is not necessarily different from AAA.  You can be both.

Similar to music, "indie" lost its literal meaning and took on a prescribed meaning by the characteristics of the games (or bands in the case of music) it largely described.

So basically, an "indie" game is a small scale game which is typically sold digitally instead of through retail. I'm sure that definition could be tweaked to be a little more appropriate but I think its pretty close.

The Witcher 3