Baseline (Widescreen) Solution & Issues
Native. Select your resolution from the in-game General Options' drop-down menu.
FYI settings are saved in Engine.ini which can be found in
(XP) C:\Documents and Settings\\Application Data\Ubisoft\Anno1404\Config\
(Vista) C:\Users\\AppData\Roaming\Ubisoft\Anno1404\Config\
Each of the campaign's maps is introduced by a "matte painting" cinematic that is Hor+ in widescreen. It's unusual to see 16:9 2D animations that get cut off in lower ARs (instead of being letterboxed). One may wonder whether the devs intended these to be letterboxing-free in any and all single-screen ARs, or if this is a minor design flaw.
However these "almost still" cinematics with a narrative voice-over are little more than animated loading screens actually (the intro scrolls to the right, these don't). And after all, "more to see in widescreen" is what we want, right ?
The main menu's animated background works in a similar way. One has to admit black bars would have sucked big time here.
Ultra/Super-Wide (21:9/32:9) Specific Solution & Issues
Eyefinity / Surround Specific Solution & Issues
Native, Hor+ gameplay.
Real-time cutscenes : Hor+
Intro : pillarboxed
Matte painting cinematics and main menu background : sadly Vert-
HUD : scales correctly, exploded (i.e not centered).
4k UHD Specific Solution & Issues