Musically, here is my first reaction.
1. This is too "flat" to my ears, not enough musical variety. To provide depth, there are several things you might try.
a. Do another line of music that mirrors parts of the existing but an octave higher and/or lower.
b. I'm hearing too many notes. In some of the parts (probably the chorus) take some of the lines of music, and use only full notes, or half notes and get rid of some of the quarter notes. It won't change the flavor of the music, but will lend (imo) gravity to your chorus - (or wherever you choose to lengthen the notes. I know it's a happy, bouncy kind of song, but some gravity somewhere in the song will emphasize that, and I don't think it would detract.
c. Throughout the song in selected parts, take an additional instrumental line, and create compatible emphasis notes (consistent with the existing, but with emphatic type instruments (like jazz piano or other maybe some other strike type instrument) that are 1/8 note offset from the existing and used only in the "3 and 4" positions in selected measures. This probably won't make sense, but if you are interested, talk to me about it and I'll show you.
2. To create even more variety, you can (not necessarily in this case "should" just "can) look for alternate timings on the vocal. In other words, change the flow, by creating "silence" between the vocals to carry and emphasize. Pauses (unexpected silence held a beat longer than anticipated) creates surprise and interest.
I hope this helps. Let me know if you have questions.