Changelog for Update 1.03 (added 02 October 2017):

⦁ Unlocks being saved properly (will also unlock for people who already should have gotten unlocks)
⦁ Fixed progress blocker bug in Mausoleum
⦁ Fixed issue where some keys on the keyboard were not bindable
⦁ Tweak to make sure player shouldn't be able to end up below Bridges level
⦁ Fix for Key Waypoints activating too early under certain circumstances
⦁ UI and text tweaks
⦁ Visual updates and minor gameplay bug fixes/tweaks

Changelog for Update 1.04 (added 20 December 2017):

ECHO now supports Razer Chroma peripherals: Experience the blackouts across all your Chroma peripherals! Palace ambience color corresponding to which section you are in, as well as active keys, hurt sphere, stamina- and recharging-bar. It’s cool!

Also, now you can re-watch cut-scenes and Verses from the Level Select Menu. (Cut-scene “seen” status for being able to skip should now save properly as well!)

Window mode, resolution and aspect ratio now only gets applied when user presses an Apply-button instead of applying while changing values in the menu, which sucked.

And, of course, minor bug fixes and visual updates.

Merry Christmas!

Changelog for Update 1.05 (added 22 December 2017):

* Added Ultra Widescreen and Multi-monitor support!

Does this also include support for 16:10 monitors?

I neither am affiliated to the devs nor own the game, just a GOG user posting changelogs as they're made available here, so can't answer, sorry. I suggest you contact GOG Support or ping JudasIscariot, and then perhaps post any reply/clarification you get.