Secret of Evangelion (シークレット オブ エヴァンゲリオン) is a video game that was developed by Cyber Front and released for PlayStation 2 in December 2006, then later ported to PlayStation Portable and Windows on June 28th, 2007. Both of the later releases included extra illustrations unique to the re-release, as well as a bonus quiz game. The game is based on the Evangelion anime TV series as well as The End of Evangelion movie.
This is a visual novel adventure game that follows the original character Kyoya Kenzaki discovering secrets of the Human Instrumentality Project and other events regarding Evangelion Unit-04. Depending on the choices made by the player, there are 10 different endings that can be unlocked.
Source: Evangelion.Fandom, "Secret of Evangelion", available under the CC-BY-SA License.