Just in case someone else has this game only display a blank window with sound (bug from Nvidia clashing with Godot if I understood well), this trick solved it for me (Windows 7): type "cmd" in the game's address bar in the explorer, then in the console type "[game].exe --video-driver GLES2"
Turns out the game still lags too much to play on my potato laptop, but it works. If the window is stuck on the upper left of the screen of something, hold "shift" and right-click on the game's task bar icon, then click "move".