In all honesty, I would suggest downloading the trial and finding out your own opinion of it. The full game is pretty well the same as the trial, there's just more to it (game keeps going and there's multiplayer). Personally I quite enjoyed it and would highly recommend it. If after having tried it, your still unsure, you could just wait for A World of Keflings to come out (its the sequel) which is supposed to be released before the end of the year.
Thanks to Spazaz Man for the sig!