This is a great start, I love the environment artwork and the little flourishes like the barrels shaking.
I kinda disagree with the earlier commenter, I think the lizards getting stuck on the environment is interesting, especially when you can sort of build a trap for them by selectively destroying crates. In a full game you could really expand on that by letting the player push crates around.
One thing that did feel lame though was that the lizards didn't react to being attacked from behind. If sneaking up on them let me get one free hit in, that would be one thing, but beating the entire level like that?