I like the art and the details you encorporated (such as rocks as obstacles). I do suggest making the pixel sizes of the frog and snakes identical to the grass to ensure that they look like they belong together. The map is a bit small, perhaps a very simple procedurally generated map could be useful. Furthermore, the gameplay itself is a bit bland if you consider that there isn't a whole lot to do. There is some consideration for adding other cool gadgets and powerups that can give you levels to make this almost a roguelike experience. Overall great game but needs more depth. Good job!