I didn't really get the relation to "Seal Lullaby." The piano part is similar with running eights, even though they aren't in the bass line. The only thing that I find similar is the obnoxious key. I can't really sugar coat this, but keys with anymore than 4 flats or sharps make me want to shove my piano out a window. Those keys are okay when it's a capella or for 10-20 measures in an instrumental ensemble piece, but for choir with piano it's somewhat unneeded.. I guess the piano part is quite easy in the bass line which provides a little room for difficulty within the right hand even though you could get by in this piece with moving your hands very little. There has to be some more creativity within the piano part, and trust me, I know it's tempting to write the same thing for the piano through the whole song, which you did, but some variation can really add to the song.. Now onto the choir parts. There could have been more range within all the parts. Ignore books that tell you what basic ranges are for the satb. No book can tell you that the lowest note you can write for a bass is A, or the highest for soprano is E. I've sung songs that for me (a second bass) have gone down to C# (Lux Aurumque). I have also sung songs where the soprano has gone up to a high C (My Soul's Been Anchored in the Lord.) Of course these are the extremes of ranges, and not all choirs have voices that can perform these notes, but I can tell you from the second bass end, that composers that write low notes for us, are the composers that we like better. Next we can talk about the harmonies. Obviously they are beautiful, but make more use of the fact that there are 4 different groups of voices that you can split into 2, 3, or even 4 parts if you would like. Make words sparkle with tone clusters, use minor chords to disrupt any predictability within the chord progression. There is definitely some great potential for this piece, keep working on it.