Maybe I can give a rating after the next version, for now its a bit bare bones and i dont want to give it "only" 4 stars so ill just review it in comment. With some variation and progression implemented it can easily be a 5 star in my book, even if not all aspects of it are 5.
Art is good overall, she has a very overt doll like appearance. I really like her eyes and thighs. My least favorite thing about her is the pubic bone. Since she is so doll like- I was like "why does she have a keyhole at her pubic bone?" Sorry, I know its not a keyhole just the sytlistic choice you went with. 4/5 good enough. Outfit is cool too.
Animations could improve but its already why im entusiastic about this game - love seeing pov animations.
For example the slow stroking rhythm is a bit too wild in varying the movement. Generally the loops arent seamless, but its not like they have to be in order to be enjoyable. Something like the pov boot must be very hard to do so well 5/5... doing palming 5/5.
Tasks: I liked their lenght. I have some ideas for variation -i know its already planned but maybe you find a new idea. Like stroking with two fingers, just the head, palming with a cupped hand, doorknob (twisting the fingertips along the ridge), sliding the flat palm over the head from the tip of the middle finger to the wrist & repeat, Reverse grip stroking. Very slow but very tight strokes can be also fun. Slightly painful idea, pushing up your balls and slamming the stroking hand into them with every stroke.
People are already asking about cosmetic variations and customizeable fetishes but I think your time is best spent on fleshing out stroking methods and animating them. I kinda focused on headplay here - for these types of tasks it would be probably best to instruct to lube up before the first one.
Maybe its just personal taste, but what I really like is this fine tuned control. It means following the animations as best as I can.
Sessions or larger sections of a longer session could have their own theme, like alternating between head and shaft, or red light green light, or firmly rubbing through the pants quick & slow etc.
The UI:
The visual indicator on the sides would be better off not moving at all to the rhythm, but are good to show time remaining for the task (when you intend to).
I think the pacing is kinda good, my idea for perhaps improving it is putting small-ish icons (buttons) on the side/bottom of the animation screen. This way rating a task or signalling failure / orgasm could happen with a single click during the task and tasks would follow eachother without a break. Except when break is intended it could be done with the click-through text. So only the "success" button would be eliminated but it would be more hands-free to play. Orgasm could be signalled immediately this way.
These are just some random ideas, Im pretty sure the game is on good track already since obviously JOI is the focus and variation is coming. The game started with some story elements which I really liked, as I mentioned in the beginning im hoping progression will be implemented, for some reason that is much more enjoyable than pure randomness. Perhaps because it simulates a more personal experience. This would mean more one-time dialogs and perhaps increasing difficulty and challenges with progression. Is this the direction you are planning? You already mentioned milestones and thats the other reason im hyped besides the pov-joi thing.
Keep up the good work!