Welcome to Shifter Labs 4.

You find yourself at the very bottom of a fathomlessly deep bunker, with nothing but your shirt and pants on, and definitely no memories of how you got there, or why you're here...but one thing is for certain: your very humanity is at risk.

The surface is over 200 sublayers above you. Within each layer are traps, puzzles, people, and monsters that all want one thing: your humanity. Around every corner is a risk of bursting out into feathers, your claws tearing through your shoes, a tail pushing out the bottom of your spine, a second, third, and fourth set of eyes. Along with that, a powerful family has their eyes on you as you climb the layers, willing to use you for their mysterious plan.

And on top of everything, where are you anyway?
It's clear you will not escape this bunker with your humanity intact...
...but is that what you really desire?

The Shifter Labs series is a set of adult, story-driven adventure games that can be played in any order that involve you exploring a fairly linear, segmented world filled with puzzles, characters, and traps. The aim of the game is to reach the end and escape wherever the player finds themselves, however the secondary goal of the game is to collect transformation scenes, which involve the player turning into various creatures…in not-safe-for-work styles.

You do not need to play the other three games to enjoy this one. Outside of some vague references or lore hints, all SL games are isolated stories that can be played in any order.

This is a NSFW game for adult furry audiences. It was made in Twine, and is a game that runs using HTML and JavaScript formatting. I was inspired by games like Changed to make a transformation-based adventure.