Looks cool - I'm actually working on a match 3 game where you match fruit to make drink... but mine is traditional grid based match3, and is for the Atari ST, which is a 30 year old, 16-bit system
One thing that I think would be awesome is if you complete the level, the berries get blended into a smoothie... like a thick purple liquid fills the jug from the bottom up, while the berries explode. I think an effect like that could be your hook - these games all need a hook, something to make people go "HA! What's that game?"
Might be cool to have powerups as well, but as ingredients... like sugar cubes, peanuts, candy, etc... whatever you can think of and can implement. A lot of the time, it's seeing what comes next that keeps people playing these games. Think of ways to constantly reward the player - spread out your content so there's always something new for players to look forward to.
Rotten berries that you shouldn't match might be a nice idea - have some strawbs with worms in them.
Static backdrops are the devil - from the looks of things, you could have foliage moving, leaves falling from trees, snow... with just some simple particle effects you could really expand on the environment.
Have different jugs! - that could be the level theme, like the standard lemonade jug you have, but add more jugs, and things that shouldn't be jugs, use them as jugs... like fish bowls and whiskey bottles and a colostomy bag (K, maybe not). As I said, it's the promise of new and interesting environments and dynamics that keep people playing these games. Nobody would play Candy Crush if all it had was candy, and no funky new candy within a few levels.
I know adding a load of content is just a load of extra work, but consider that it might pay off big in the end - it might be totally worth it.
One last thing.... refraction. If you can render that to an image, then render a sprite with that image plus a mild normal map offset, add on a shiny jug image over the top, it would look like refractive glass, would look incredible with that graphics style I think. It already looks good, but I think going the extra 5 yards would be worth it, would make it really stand out.
