I'd say you have ~ 50% chance of successfully spreading this game. You must spread it manually (unless jackfuste helps you out with a hex-edit).
If you want help attempting this, let me know. Your first step would be to try & find where game's chosen resolution is stored. Spreading it would be made easier if you knew the game engine (worth a look around)....
Also check this site out if you haven't, the notes under "Issues fixed".
http://pcgamingwiki.com/wiki/RevenantIt says:
5. Game screen is stretched horizontally on modern monitors Revenant uses fixed 640x480 4:3 ratio resolution which does not scale properly on 16:9 screens
Assuming you use NVIDIA gpu
Open Nvidia Control Panel
Go to Display>Adjust display size and position window
Set 'Select a scalling mode:' to 'Aspect Ratio'
Set 'Perform Scaling on:' to GPU
Apply changes
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Above note may look decent, but doesn't appear to address spreading the game to fill. Likely margins, not ideal.