In addition to being difficult to record Dogfighter by OBS for reasons of not being able to alt + tab, otherwise the game enters an eternal black screen, I can't activate the Livesplit timer. I would like to know how you managed to record your run, so I can submit one too (this text has been Ctrl+V'ed in google translator).

Hey there, sorry about the late reply. I need to fix my notification settings clearly...

If you open Livesplit, right click the window and click 'Settings', there is a box called 'Global Hotkeys'. This makes it so that your start/split hotkey works even when in a full screen game. That should help.

Mr_Mary has also made a guide on how to run the game in windowed mode. Simply download and install nGlide, and press 'Alt+Enter' after opening the game, in order to run it in windowed. However, I recommend using a keyboard key to start and stop your timer :)