Darkeden is a great game but it does not let you choose a HD resolution in the settings.
You can get around this though, by following this guide:
- Browse to “steamappscommonDark Edendatainfo”
- Open “resolution.inf”
- Set the resolution X to 1920, resolution Y to 1080, then save it.
- IMPORTANT: Right click the “resolution.inf” file and click “Properties”.
- Tick the “Read Only” box (this will prevent the game changing it) and click “OK”