The Nix & Emi romance scene is available in Version 0.5.0, which is currently Patreon-exclusive. The latest public version on itch.io is 0.4.1, so that scene isn't included there yet. Once Version 0.6.0 is released on Patreon, Version 0.5.0 (including the Nix & Emi scene) will become available for everyone on itch.