I have a love / hate relationship with that game.
The idea itself felt very fresh, same with execution, and the design is REALLY cool. Another good thing is that the game has something of a learning curve. Despite having to restart all over, due to failures, and despite being pissed off and ragequitting many times while playing, I did enjoy it a lot.
I certainly wouldn't mind a sequel.
Getting all the medals wasn't an easy feat, and ironically, level 6 is the hardest to collect all of the garbage rocks, despite it seemingly looking as the easiest one. The reason for that is because the space between the "letters" is not wide enough, and it's easy to miss some of the rocks.
Also, while the game is challenging, it's fair in a way that you can learn the patterns and how to use the levels to your advantage. In other words, you get better the more you play this game. I would also advise taking long breaks, as the game can be very exhausting. I think that everyone who wants to get all of the medals, will get them, if they aren't lazy.
To get secret medal: during survival (post level 10), you just have to not move at all for 60 seconds and survive. The easiest way would be to go in some corner.