Wow. You have a gorgeous voice!
You went slightly off-key every now and then, but for the most part, I was really impressed!
Very nice use of vibrato!
I'm gonna give you a little advice, but this is more detailed because it was really great!
You were a little off beat. It's really hard to be on beat without accompaniment, so it's not a horrible terrible thing or anything.
The only thing I could really suggest is to do a little more. What I mean was, it sounded amazing, but it sounded similar throughout. Maybe play with the volume a bit or something?
Overall, great job!