I like all four games.
Still there are some issues.
1. Eluku games are hot, but the stretching is not permanent, usually when the most extreme stretching happens, a gameover also happens so...
As for free cities, it is rather fun, but if I remember l last I played there wasn't much in the stretching department, it didn't had any effects beyond some minor scene changes I believe.
Lilith throne has a gape system and all, but kinda requires you go out of your way to get a character hole destroyed, since the default human characters can heal 100% back no matter what gets stuffed inside them, only deliberate transformations can change hole sizes permanently.
Also there is not much effect a character having a gape, the games DOES have some effects but not much.