Thanks!
The tentacle indeed uses IK targets. For the visual, i used a 2 camera setup: The secondary camera records everything except UI (lighting, sprites) onto a render texture. I then use a shader to sample the final color with this render texture, the final result is displayed by the main camera.
I tried to improve a bit on the visual aspect for once so the actual game content is "a bit" lacking.
Ennemi attacks do have an effect: they reduce your progress, but they cant make you loose.