I find it highly unlikely that HARLEY QUINN only has a Dance, Strip and BJ scene, shes in like the top billing of DC characters people wanna fuck
The development of this game has been all over the place. It started development in 2015, and Harley was introduced that year, almost five years ago.
However, instead of finishing the relatively small amount of girls in those early years, Sunsetriders7 took on the herculean task of adding pretty much every female DC character to the game. This led to the game having a lot of girls where you could progress to BJ at most, leading people to joke that Lex was uninterested in sex. (The first time the player got to fuck someone was a random anal scene with Livewire in 2017 or 2018.)
Stargirl is probably one of the worst teases. She was added to the cells in 2017, had a dance scene added, and... that's it. That's all the cell interaction you can have with her for the last three years. Black Canary and Huntress have been in the game from the start, but don't have any cell content at all.
One thing to keep in mind though, is that the cells weren't part of the original plan. The only girls you were supposed to interact with at LexCorp were your henchwomen.
The game also ceased development in the first half of 2016 after Patreon forced them to remove the game due to copyright stuff. That's the story behind the name - it used to be Injustice Unlimited, a play on Justice League Unlimited (the show it's based on). It returned as Something Unlimited after they realized they were safe if they just tweaked the name a bit.