This one has great replay value. Should probably draw the refresh bar last so it doesn't get hidden in the ice. After the first hurdle the game mechanics no longer scale so you may have to introduce new elements, but it was still enjoyable to box in like 40 dogs into a solid cube in the 4th-5th wave :D

nice solid gameplay. add some music and a story

Wow this turned out really cool! I thought I was pretty clever but those dogs always seem to find a way out D: