[Cthulhu_]

It's probably the fine line between parody and copying; the ikea game was ruled too much like a copy, GTA was ruled a parody.

[Karliss]

Nothing was ruled so far. IKEA lawyers just looked at it said they don't like it, doesn't matter whether it's valid parody or not. And in many cases it works, because the potential cost of defending in court is too much.