Of these five levels, my favourite is level 4. The concept is interesting, although it feels a bit too short.
The others, meanwhile, while they may have good concepts, they feel too short. For example, in level 1, the monsters never really pose a threat to Chip and level 5 involves waiting for the tanks to stop moving, then exiting. Your levels may benefit by being more complex. Still, this is a good set, considering it is your first.