Theatre or Theater, and Favor or Favour

Now, I'm Canadian.. But I'm developing a game that hopefully will get some worldwide attention.. so I've thinking a little bit about how us up north talk and spell.. In Carthage, there are two words specifically that I'm concerned about Favour and Theatre, or if your from the US, Favor and Theater ... I'm a little concerned that if i don't spell these words the US way maybe it will annoy backers enough to not want to support/buy my game ... but on the other hand, I'm a proud canadian, and it might bother me to not have the "correct"(*subjective) spelling in my game ... I'm conflicted.. 
​ - Luke