Hello, invaders. It’s been two long years since I last tackled a rather peculiar issue regarding difficulty selection when starting a new game in previous CI games. Back then I also opened a thread here, but the mystery remained unsolved: Can't select difficulty as of late in Steam versions of CI3, CI4, and CI5
Recently, I remembered Chicken Invaders and the problems I used to have with the Steam versions, so I thought I’d try tackling the problem yet again. From fiddling with controller settings, messing with cloud saves, and even downloading older versions of the games’ depots from the Steam command-line tool (thanks to SteamDB); there’s nothing I haven’t tried. None of these efforts were fruitful. Well, not until today, anyway.
The actual problem has revealed itself to me this time: It was the name of my Steam profile. You see, I used the special character 
as the first character in my Steam profile name, which seems to be causing the issue. If I remove the from my name, or even make sure that isn’t the first character of my name by preceding it with a normal character, the difficulty selection problem goes away and I can play the game normally.
That’s definitely a game bug and it even seems like a potential vulnerability in the hiding. Might want to have that checked out. I’m too lazy to try fiddling with other special characters and test the limits of this bug as I’ve already exerted too much effort with all the Steam hackery while trying to locate the source of the issue. Quite frankly, I’m not too interested either, I’m just happy that I finally managed to solve the problem. Perhaps this time I’ll actually play through the games, as last time I didn’t take kindly to being forced to play on the Rookie difficulty. 
Cheers
Bug