Hi ! Something about thi GUI : add tooltips for everthing. IE, the big arrows with the sneak in between, bottom right, tooltip could say "lift", "sneak", "drop".
I’m not fond of voice and robot style. Could be simply "blibabjzz" noises so it’s international and way easier to fit with any text, keeping a comic aspect.
I usually find tutorial quite useless, and often over done, for many games that don’t actually need them. A simple page with some explanations would be enough. Less time consuming to work on, more time to actual gameplay.
What i’d like to see first beside accessibility options (key rebinding etc) is more precision en everything : target, flying, shadow to spot and be spotted, interaction etc. All feels a bit clunky.