I really like the sounds (particularly the "Chooooose... youuur... beeet..!" one). 
The loop works, gj.

For the gameplay, I am not really fond of gambles. But of gambles with info? Oh yeah!
If you continue working on it and you like gamble with info too, could be cool to have some stats for each spinner (speed, atk, defense...) which could influence your bet.
Of course, it would mean damage system would depend on something (like point of contact between spinners).
And you could upgrade your info gathering with your money (like maybe you have GOOD/BAD for stats at the start, but you can upgrade it for a particular stat to a rated from 1 to 5, then from 1 to 100, etc). And unlock new stats to see of course.
And lastly, choose how much you want to bet, have a rate depending on total stats from each spinner (so you can play it safe, or you can go high risk high rewards, because you know this type of spinner is reaaally good on this arena )

Congrats on making this game for the jam!

I like the effects and that you can use your money to buy arenas, nice touch. I would love some more gameplay mechanics, even something as simple as "click very fast to spin your Beyblade" before each round. 

Congratulations on your game! 

There's not much to do other than betting and purchasing, I believe, arenas. It does have some nice animations and I particularly liked the audio/voice design. More interactivity, like being able to actually spin the top yourself, might make it more fun!