Eurogamer gave 8/10 to Ace Combat 6: Fires of Liberation in their review:
Ace Combat 6 still can't quite mark itself out as an essential game; it's certainly true that the series is moving forward again, and we're delighted to see it, but this is evolution rather than revolution. Those who weren't enamoured with it in the first place will find nothing to change their minds in Ace Combat 6, and that's fine in its own way; a series update that delights the fans is no bad thing.
More than anything else, we're just happy to have another Ace Combat game we can genuinely say we really like, rather than just saying we don't dislike it. The series has rated a categorical "meh" for some time now; but no longer. Ace Combat 6 can be our wingman any time.