ColaPepsicle: How does localisation work exaclty? Starting the game in one language and then switching to another appears to change the onscreen language and some of the textures (no restart performed) but not all.
GUI design
Pause menu: The word "Paused" appears in the same font style as the other menu items but it is not interactive.
Maybe change the formatting or case, e.g.
PAUSED
*Paused*
Also if paused on a white background white text will not appear very legible.
Maybe add a soft dark drop shadow behind text?
German: the pause menu text is not perfectly centered and the white highlighting rectangle does not fit the width of the text. Presumably it set to a fixed width. Why not set it to whatever the width of the longest text is (varies between languages) and then add x amount of either percent or pixels left and right? See screenshot.
The localization swiches all dynamic texts, but in-world texts such as text on a door or similar the level or game has to be re-loaded by either a restart of the game or a level change.
If you set language when starting up the game it should work just fine when pressing "New game".