Hello,
I think there is a small bug in lesson 5 in the following code:
IF py<en.eny
en.dify=0-RND(3)
ELSE
en.dify=RND(3)
ENDIF
There is a chance that the speed of the enemy is 0... and it will stay in memory, but outside the screen...
I think it should be something like:
IF py<en.eny
en.dify=-(1+RND(2))
ELSE
en.dify=1+RND(2)
ENDIF
Voilà !