Absolutely Phenomenal
This is among the best submissions I have ever seen on Newgrounds. The entire team has clearly worked their hardest to make this as good as they can, and they succeeded.
The animation is beautiful. Sparker and Aquanna really do look like they're made of fire and water, and they move like they're real creatures. And, of course, they're absolutely adorable. That horrible robot looks fantastic, too; really scary and destructive-looking.
The music by Neil Bly is simplistic, but it suits the quiet and melancholy mood of the film perfectly. You don't need a whole orchestra when a piano and drums will do just fine.
"Alight" clearly took hours and hours and hours of work from its staff, and I congratulate you on finally finishing it. Hopefully, the rest of the NG community will love it as much as I do.