I'm surprised no one helped you while I was gone, Nestorj66. <img src="{SMILIES_PATH}/icon_e_sad.gif" alt=":(" title="Sad">
Anyway, I ended up spending hours trying to resolve this issue myself and finally solved it. <img src="{SMILIES_PATH}/icon_mrgreen.gif" alt=":mrgreen:" title="Mr. Green">
Here's the example capx.
https://www.dropbox.com/s/4v7welmk7z2xf ... .capx?dl=0
Explained
1. Enemies get destroyed only when Player jumps on their heads. (e.g. Enemies don't get destroyed when Player touches them without jumping on their heads.)
2. Player bounces off after jumping on enemy's head.
3. Player can double jump to a fixed height after jump is successful.
4. Double jump gets deactivated after player bounces off enemy's head.