Unbound features an Easter Egg where Lauren can call rabbi Stone from The Shivah. Afterwards, she comments on how his voice sounds strangely familiar. Both Stone and Joey are voiced by Abe Goldfarb.
Taken Up to 11 in Epiphany, where using Joey's tie on Abe Goldfarb's portrait at the Vantini bar will warp Joey to another dimension, where every single one of Abe Goldfarb's characters from all Wadjet Eye titles up till then are arguing with each other.
The Other Darrin: Before the release of Convergence, Rosa was voiced by Sande Chen in Legacy. She's replaced by Rebecca Whittaker from Convergence onwards, and all of Rosa's lines in Legacy were redubbed for the re-release, which is currently the most widespread version.
Dave Gilbert's plan for the series originally involved ten installments in the series. Some of the planned storylines of the games was later dropped or merged when the final number of installments landed on five.
Unbound and Convergence were originally planned to be one single game, but development was taking too long so the project was split.
At the end of Epiphany, Rosa was meant to meet Jocelyn. However, when Dave Gilbert learned Lauren's voice actress Dani Marco was visiting New York, he asked her to record some dialogue and quickly rewrote the scene to include Lauren instead.
Also in that game, Rosa would've met the police commissioner who was hinted to be part of Gavin's group. The scene ended up being Dummied Out.
Nishanthi was meant to have a larger role, as Gilbert had planned a character arc for her early on. However, he later decided for whatever reason that it wasn't going to work, hence her sudden disappearance post-Convergence.
The original climax for Convergence would've taken place at Times Square in full view of the public, which Dave Gilbert nixed for being too audacious.