IKEA has a trademark on STYR?
IKEA has a trade dress and the game matches their color scheme and font exactly. The building is clearly an IKEA with the exact same branding, just different four letter name.
Has a court enforced trade dress with a mock version of a store within a game?
Would a reasonable person, seeing completely different letters actually think IKEA is sponsoring the game?
I would give IKEA almost a 0% chance of winning that case if both sides had equally sized pocketbooks. (see E.S.S. Entertainment v. Rock Star Videos (2008))