Darkland by Laura Vega:
 
What would you do if you woke up in a deadly game, relying only on your instincts and a mystical bond with a dangerous being to survive?

Cassie is trapped in a shimmering crystal cage, deep within Darkland, a magical theme park ruled by goddesses who revel in human trials. Armed with only a mysterious key, she must navigate a world where reality shifts and danger lurks at every turn. The mirrors taunt her with eerie reflections, each one hiding secrets she must uncover to escape.

As she ventures deeper, Cassie crosses paths with Khaos, a god of strategy and mischief. His cryptic guidance could lead her to freedom or pull her further into the game's dark grip. Can she trust him, or is he just another piece in this twisted puzzle?