First, navigate to the game's installation folder, it will be under Common\Trickstyle in SteamApps or SteamLibrary. You can also simply right click the game in Steam, hit Properties > Local Files > Browse Local Files.
edit "setup.csv"
Change "fov" from 90 to 100 (or something higher than 90 that you like. This game uses Vert-, so we need to up the FOV to fix that)

(Please note - I haven't tried this, but you could probably edit the wideratio in here too to support 21:9 or 16:10, it defaults to 16:9 - 1.77777777777)

Then, launch the launcher via Steam. Choose options and set the resolution in nglide as you desire.

Finally, launch the game. Go to options > graphics
set "widescreen" to "yes"
Navigate to "end" and hit enter (do NOT hit back).

Except for some stretched HUD elements, everything else should look just fine.