VasiliyFamiliya (./33) :
Now you can see, how insane values use to be accepted with enemyX variable after player's stepping over some places of scroller

It happens because you use variable width and don't clear the display. So if you display "1234" then "567", you get "5674".

Quick-and-dirty solution: add some space characters after the number.
Better solution: either clear the display, or use fixed width.

Mega Shocked (./32):
(enemyX<320) + (enemy_spr.maxWidth*16)))

This makes no sense.
Use parentheses and temporary variables, it will make your code easier to read and make bugs easier to find.