If you look in the console there's a lot of "Flash" errors in red, some of them mention GotoAndStop which is a command used in Flash's ActionScript language
If I remember correctly Crysis 1 had these actionscript errors too
Crysis as a flash game? lol?

The Nanosuit Showroom is flash actually
It's made in the Sandbox Editor and is used here on the page AND in the game
And btw. I think the menu is Flash too

Most games today use Scaleform combined with Flash for UI and menus.