First of all thanks for posting your work on TSR. It can be difficult to receive constructive criticism especially with regards to singing, but it is good that you have done so. I would agree with the above poster. First and foremost in order for us to offer more detailed and constructive criticism, you will need a better quality microphone so that we can hear more clearly what you are singing. Singing a capella is difficult and probably one of the hardest things to do within singing. I would say that, at times, your voice sounds a little flat and I would try to ensure that you are stood up when singing, if you aren't already. Try to 'go' for the songs a little more as to remove that sound from your singing altogether. I'm not able to comment on pronunciation since I don't know whether you are pronouncing it right, but I would try to ensure that last consonants are always sounded out especially in a song like this where you can't really get away from it. Also try to add a little more enthusiasm. You are doing well, but you need to enjoy the songs and capture that enjoyment in your singing so that we can hear it.
A great attempt. Perhaps choose a song which can really demonstrate your vocal range for your next piece.