Hey the game is already pretty good, but I feel like it could use some more features like rotating her in more than just one position (like doggy in the air or even upside down) another thing is that the tentacles bend at odd angles sometimes. IDK if it is preference but a more flowing wave like design would look better in my eyes. Another is more types of tentacles (tickles, suction, etc..) which would spice up the game. Another improvement would be to have just a button designed for the type of tentacle instead of having multiple for the same type.
Also the restraint tentacle should have a lock/unlock function to make to easier to move them around instead of making them disappear when you want to change a pose. Also instead of the girl constantly covering herself up after you release her you could have a lust/fatigue meter than makes her either not cover herself up or even fall to the ground in exhaustion.
That being said it's a pretty good start to this type of game.