This game is very addictive and fun to play. The puzzles are challenging enough to make you think but not so hard that you want to quit, which makes it very engaging to play. The other thing that is awesome about this game is that you can enjoy playing it and gather energy capacity as well as regeneration speed without breaking the bank, in fact you can move at a good pace without spending an actual dime if you don't really have the funds to invest in a game. Very worth playing.