Even if it was unfinished, there are interesting things to notice. The speed decreases and we have to choose the good path in order not to be blocked or slowed considerably (like in the long stairs). But level design wise, I think some efforts could have been done to really reward the player taking risks to be sooner at the finish line. There's something to exploit here.
I can't comment on the graphics as they are too basic. Next time you should at least use free assets that you could modify a bit if you want, if art is not your best.Or even better, team up with someone.
I'm sure you'll do better next time. The game development is a long journey that can be very gratifying. :)