Disappointed With This App

This is a fun little game to pass the time. Afew things I thinl would make it better. I wish you couldnt access the next level until you successfully escape the previous one and also instead of the clock being stuck at 9:99 for the endless level i wish it counted up so you can see how long you can survive for. Beyond that I just wish there were more levels. Or different ways to unlock characters, weapons and upgrades. Rather than just collecting money in the game and buying them.