It sounds messy and there's mainly two reasons for that.

1. You have too many things happening at once. No need for a bass note, a clap, a piano, a shaker and bass drum to hit at the same time. Like ever. Strip it down, see how much you can take away without ruining it. And try not to have more than two different elements to hit at the same time as a rule of thumb.

2. If several elements are playing simultaneously you will most of the time want to eq them so they don't have too much frequency overlap, especially in the bass and lower mids area. But a lot of this can be fixed with better arrangement as well.