If you have ever wondered how collecting coins / mushrooms / rings / whatever could give your hero an extra chance of pwn'ing the big boss?
Here's how Bouli solved the problem for his hero friend Bilou ... Behold the smart combination of a bio-fuel generator with the standard emergency tele-transmatter ^_^
Just what you need to get extracted from a dangerous zone for medical care and then beamed back to the last receptive crystal that has been "activated" (aka. checkpoint)
The energy of 100 apples is required for a two-way beam (there and back), but of course, you might find other stuff that provide more energy at once ...
"bonus" you gather are automatically beamed to feed the bio-fuel unit, of course :P