Pros: Interesting design
Cons: Items sometimes a bit tricky to vacuum, Overall time left wasn't apparent at first
Suggestions(One for each category):
Easier view of overall times left (possibly timer that follows you)
Vacuum could work a bit better (Many times driving past items and vacuuming does nothing even though the animation is right over it)
Better audio balance
Possibly animations for the items "turning into" the nanobots
Secret hoover-able things (maybe like bags floating in the air etc.. since currently all the collectables are ground level)