Puzzles are great. I really enjoy core mechanic and mechanics combination. BUT - it's not a good point to mix genres that way. I talk about levels, where you need to throw penguins and run fast to block flying penguin. If player comes to play puzzle game - he will stop playing on levels like that. (As example - boss fight in Portal game was more like FPS boss fight on first playtests. Than they decided to make it the same slow as hall puzzle game to not change tempo). But in general - game is perfect. Really enjoyed it