for a first "good" game...
as someone who doesn't program things, i wont rake you over the coals for experimenting. the game could use 5 somewhat simple improvements to get a better score.
1) add something passive (music or sound effects) preferably not the 1 minute midi crap everything else has been using for the past decade.
2) theme (that is to say) blocks are a way out of work, not a way to show off. draw pictures, make monsters, do just about anything but objects i could make in paint.
3) add a level system or even a points bar to compare runs, track progress, or challenge my friends to beat.
4) ad some form of plot device, no matter how obscure. your on newgrounds, just about anything works here.
5) have fun with it. if your looking at this saying "I have to do all this?" you might want to consider a different direction in computer sciences.
I like the way the random block generator worked, with the above improvements maybe you'll be seeing front page??