Is there any way to take a screenshot in this game? There is a "screenshots" folder in the Hard Reset Redux save location, but when one looks at the Key Bindings of the game, it doesn't show a screenshot button. I tried pressing F12 and for some reason it gave me the achievement "Engineer." Does anyone know what that means? Apparently F11 restarts the level.

I don't know. The only thing that worked for me was using standard print button in windowed mode.

see this: https://www.gog.com/forum/hard_reset_redux/f12_unlocks_all_weapon_modes_for_the_main_gun_oo/post1
"engineer" means having all the upgrades for the CLN weapon