My best bet is that is that you only THINK you're hitting TILDE. The game listens on a button which it assumes it has been marked as TILDE but, in your language, it isn't. SDL apps often go confused with non-standard keyboard layouts. I see hungarian has the tilde on the '1' button (according to wiki). In other words, you should try thinking in international layout (see here).
I don't have OpenTyrian installed right now so I cannot check myself but you could try: - the button to the left of '1' (tilde on QWERTY-US), supposing your keyboard layout leaves the numbers at the top row.
- the button to the right of 'L'. I don't know what locale puts tilde here. I'm not even sure it's tilde in the first place but maybe it's worth a try.