It's quite nice, but for me there was to little variety between the levels. Also if you complete a level and click replay (instead of next) and than go back to the level selecter, the next level is still locked.
Hello. I've been trying to trigger the bug you encountered but it doesn't seem to occur. i.e. (1) Complete the level. (2) Press retry (3) Exit via the home button on the upper left hand corner to Mission Select Entry is still granted to the next level.
