And with that we now have 2 games to sell, increasing our profits. With this they now have people talking, collaborating and trading. These two lines have caused many arguments of superiority over the years. A simplistic switch to me seems quite impressive and powerful.
Right, there are a number of differences between Red/Blue. The most well known differences are on the title screen and which Pokémon you can find. But there are other differences that need to be taken into account, like some palettes and the game corner prizes.
Not yet. When stag019 is done incorporating his red/blue differences, the blue make target will compile correctly. Then the blue ROM md5 will be added to the README. But until then, the blue make target is definitely not working.
The original comment seemed to trivialize the differences between the games. If you wanted to you could say something similar about any conditional branch but doing so completely ignores the differences between the branches. Assemble time checking for _RED and _BLUE makes it easy to switch between versions sure, but the it doesn't say anything about the actual differences (large or small) between the versions. A simple flag like that can be used to build vastly different programs. Also, given that those flags are macros to begin with tells me we don't even know if that was how the originals were differentiated; you can't really disassemble a macro.
edit: I don't mean to be an ass about this. There's certainly a sort of poetic quality to the use of a flag like that to switch between versions but I just thought it was worth also pointing out the work it took to do so.