Good puzzle game, but steep learning curve
Well designed puzzle game has a couple of drawbacks. Here's my list of cons and pros:
o The instructions are a little hard to find considering most of us just dive right in to a game expecting a "step by step" tutorial if no "instruction" button is on the main menu. FOR OTHER PLAYERS READING THIS, CLICK ON EXTRAS FOR THE "HOW TO PLAY BUTTON. Alas, even that isn't very helpful and a little trial and error is still required. EVERY PIPE NEED NOT BE USED, JUST DON'T LEAVE ANY OPEN ENDS ON THE "FILLED" PIPES.
o The music gets ridiculously repetitive and must be muted after only a few minutes of play (I kind of liked it at first, but it grated after a short while).
o Although I can tell there is some kind of progression to the normal mode, it's not as obvious as the zen mode and it can start to feel like one is doing another puzzle just for the hell of it. Maybe add a clearer progression or perhaps even a flimsy bullshit storyline to nudge the player along. I likes me some flimsy bullshit storylines (not really).
o I do love the inclusion of different modes and everyone loves achievements!
Overall, a very addicting game concept and it's implemented very nicely, but some menu tweaking and/or inclusion of a tutorial would definitely raise your scores. I look forward to your future submissions!