suggestions for the final product
first off, no music. Chances are the place will be noisy enough with ambient music, people talking, consumables being prepped. The sound effects are cute, but you might want to get some originals done, even if you're using the sound of one thing for another, like you could actually use sounds of the coffee shop to represent the things you're putting up, like the sound of steamed milk being dispensed to be that monster's roar. Also, there's no point in putting up a thing that says 'click this to go back to the main menu' just put under or next to the caffeine 'main menu.' Also, a voice might help, so having a voice actor record some phrases: select from the options below to view the type of item you wish to buy, select from the items below to place your order, touch the caffeine molecule to return to the main menu, and so on. Also, scan in a few pics of various items you'll find in the coffee shop. For instance, take a pic of a foamy cup of coffee with cinnamon from above, dull down the colors a bit, and suddenly that moon is a cup of coffee, and with some creative coloring, a similar pic could become the earth. Likewise, make the satellite a creme pitcher or a grinder for cinnamon/chocolate/etc. For the monster's claws, make those out of biscotti or muffins or something. If you can keep the coffeeshop and the scifi themes tied tightly together, people will be drawn to the cleverness and enjoy pointing out to friends the little twists on things.
The transitions are fun, but some people want to just order a cup of coffee, so it could go either way, because they are quick. Maybe you could have a little alien wrapped around the tip jar, and have posters or statues from classic scifi movies and shows: babylon 5, farscape, ET, xfiles, tripping the rift, twin peaks, all that stuff! I wish you and her luck with it.