I don't know if the intention was to have each voice be individual like it is, but it sounds as if each voice was recorded in an individual space and then spliced together, which isn't bad but it stands out imo. If you want to unify each voice / track together, using a small universal effect like a reverb, a delay, or even a filter can make it sound as if everything is happening in the same place. That being said, it's not like a it's a law to do that. It depends on your intention.
Other than that, I like the tune, it's innocent and melodic. Not entirely sure if I'd call it Ambient, but it's a fun song nonetheless