I tried a really casual run and this is my score (again, really casual). I like the game and especially the simplicity and the time mechanics. A really smart game, but music and graphics must be improved, for now we have only one track loop and the gameplay graphics are a little different than the menu graphics (I am talking especially about the walls).
I would improve the last two levels since they are really straight-forward, I wanted more open levels like the first three ones, with 4 and then 5 birds at the last level instead fixing on one route with two birds. Also, I would change the score system. More CZD for every level and always at least 1 CZD if you do the task in 999 seconds, I don’t know if I explained this well. Think about it and congratulations again for this really solid entry!