The game is Kaiju Paradise if you want to play (roblox)

you wake up in a room…looks like a testing room…pretty big..with a glass wall, with a scientist inside on a computer…

He soon comes in through a door to do some tests…as he then brings out another human test subject…most likely a criminal…for you to attack…

”You may attack them. Unleash yourself on him….”

the Scientist said…

you notice that the human subject has his hands tied to his back…and you can attack…