This issue is generaly due to the graphic card, you can update your flash player and remove the graphic card connection within Flash settings or maybe try to play with an other browser (if you are on chrome try Edge, or if you are on Edge try with chrome)
To disable hardware acceleration read this link: https://forums.adobe.com/thread/891337
The Health Power-up also gives Score, and the idea is to maximize your Score. So it allows the player to pick up the Health Power-ups before the end of the level to help maximize your score.
 "Mutilate-a-Doll 2"){kind=icon}
 "Everybody Edits"){kind=icon}
 "Critical-Strike: Portable"){kind=icon}
 "Imperium war"){kind=icon}
 "Drop Dead: Remains"){kind=icon}
 "Red"){kind=icon}
 "TK's Survival"){kind=icon}
 "Decision 3"){kind=icon}
 "Three Goblets"){kind=icon}
 "SAS: Zombie Assault 4"){kind=icon}
 "Endless Zombie Rampage 2"){kind=icon}
 "Learn to Fly 3"){kind=icon}
I shall edit "chat" back into the game in a moment...