The hyper mode starts when ski runner catches some
few pills in speedy unbroken sequence.
This moment means that the Combo1 mode's
gained (score for collected pills is now
doubled).
If the combo of succesfully
gathered pills continues, Combo2 mode starts in a
while. No surprise what's next: Combo3, Combo4
and so on (in fact, perhaps the limit is Combo5).
Of course, every advance multiplies the score
again.
Most important here is to keep
the combo of collected pills unbroken - this
greatly increases score.
To pass through first 8 levels it's enough to use just pure towers. There are only few exceptions (from the list of possible non pure towers) - splash slow and splash poison towers. These two types are quite useful in every stage you play.
Try to take a look at my video and imitate it:
http://www.youtube.com/watch?v=24yDcqtwo7k
Sorry, that was a comment...
My advice
is to play Stunt Bike Deluxe - it's the same
game and there you can find some helpful tips.
