Is it possible to change the language to english? I'm going to my friend's place this weekend and he says the text is in spanish but it's cut off at the end of each paragraph, and there's no option anywhere in game to change language, nor a Gog language changer like in other games.
(I don't own the game, but I often help my friend with any troble he has with his)
I don't think my friend will like to read the tutorial in english, but he says he'll be better if he can read the last words in the tutorial, and maybe change back to spanish for gameplay. He has told me he got the last Gog version, but I don't know what version it is until I sit in front of his computer. Searching only gives me fix for Steam version.

In 8-bit Invaders\Data\Mods\Text, copy STUB_Master_Text_Mod_Unicode.csv to "Master_Text_Mod_Unicode.csv". That contains the default text in english, that it's not cutoff at the end of the paragraphs. Delete it (or rename) to make 8-bit Invaders use the system language again.

I think that not being able to change language can be considered a bug.

use Language=EN-US as a command line agument