For an exercise in game development, this is not bad. Unfortunately, due to the complete randomness of the coin flips, I wouldn’t call this a good exercise in game design.
If you are looking for feedback on the juice in the game: it was satisfying already, I liked the button hover effect, coin flip sound effect and screen shake. This could be improved further by adding some randomness to the screen shake and some rotation (as well as maybe having only a small screenshake on button press, and a larger one when you lose your combo). Additionally, I would have liked to see a sound effect play on button press. Maybe heighten the feel of the combo: e.g. with louder sound effects when the combo gets higher?