This thread is still very much a work in progress, I have just added most of the in-development im sims that I'm aware of, so if you have any recommendations or suggestions feel free to share. The fine folks over on TTLG already have a pretty neat thread on the same topic, so you can take a look there as well.
EDIT (06/02/2023) - Added a few more games to the list, also added im sim adjacent games in development as I felt they may be of interest to people
EDIT (08/02/2023) - Added Repo Man, not sure if it's an im sim, not enough information on the game yet, but the developers refer to it as such
EDIT (08/02/2023) - Added Cold Depth, Safe Not Safe. Deadeye Deepfake Simulacrum
EDIT (08/02/2023) - Added a section for all the released im sims so far, haven't managed to add all titles, welcome suggestions
EDIT (27/02/2023) - Delightfyl is apparently canceled, added Ultima Underworld 1 and 2 at last
IMMERSIVE SIMS CURRENTLY IN DEVELOPMENT:
RECENTLY RELEASED IMMERSIVE SIMS: