Because I'm not usually a fan of this kind of games I haven't played it, but I really find it silly how people are saying the protagonist being Mexican automatically makes this worth playing. The 'theme' of the game appeals to me as much as 'Memoirs of a Geisha' appeals to Japan, probably for the same reasons.
And apparently at some point García says "ˇCabróns!". For some reason that's not as funny as Engrish.
There's plenty of Spanish swear words, especially if you use the brutal kills a lot (stun an enemy, get close, press Square). 'Cabrons' is in there, as is 'Chupa mi verga', and I think a couple others. I actually found it kind of amusing.
The protagonist being Mexican can be seen as a big deal in that he's a latino (technically a cultural minority in the US, whatever) rather than a white dude. Of course, he's Mexican as seen through the eyes of a Japanese game developer, localised into English. The point being, I don't think it's supposed to be a real representation of a Mexican person, rather than the perception of what 'being Mexican' is to someone from outside the culture.
I mean, if we're going to get all nitpicky, 'Garcia' is a surname, you're very unlikely to meet someone who's first name is Garcia in real life. Also, Hotspur isn't a Mexican name (Suda probably got it from the UK Football team Tottenham Hotspurs, or at least that's the first thing that comes to mind every time I read or hear the name).
In any case, I like that the protagonist is closer to someone from 'El Mariachi' than yet another buzz-cut white space-marine type.