I'm not programming, but... Here's what I noticed playing this; Instead of telling you "dis sux lul 0 score".
-The green "shark" has a full 8-point movement track, while the shark you play as has only a 4. The people have this 4 path as well. Due to this, I noticed avoiding the green one was very difficult.
-Hearing this was made in 2 days makes me sympathetic. In a short time, this is a good effort... but it IS lacking. I'm still keeping in mind about the quickness of the production.
-In some locations (I.E Russia) the people blend into the backgrounds making it very hard to see.
-As many people have stated, clicking in to move your shark is a huge issue.
Overall: I've seen your comments to people and I want to say that this is a good start. You're learning the ropes and you're beginning to understand how game mechanics work. This is the beginning for you, and it does need work. I'd love to see more things from you later on.
Good luck!