Not much to say about this, really. It's a one trick pony, but it looks nice-ish.

As for the gameplay, It was entertaining for a little while, then monotony kicked in. Likewise, the DnB/Hardstyle remix of "The Llama Song" was amusing for a few minutes, then it quickly became annoying. Otherwise, there's nothing really wrong with it. Add in a few more elements and it'd probably be pretty fun.

While the upgrade thing is nice, this game seems to be have no challenge to it, you can't even die. It's simply shoot, shoot, shoot, shoot, upgrade and then shoot some more. I understand that it's exactly what the creator advertised but it still seems a little bit empty.