@Jaimie: thanks, now sorted out and reached the final boss of the Aztec level (lost there!)
I must say this game is really awesome, with good level design which allows to sometimes quit the level in panic, and on next games, when you're more skilled on this particular level and you learned the mechanics, try to reach more bonuses/lose less energy/eggs.
The parts where I "cheat" is that when I get the "baddies get revenge" chore in the hardest levels (egypt/forest/aztec) I tend to suicide because it costs so many eggs to kill them that it's better to lose a life.
Another annoying thing is that when you have 0 eggs and you lose a life, you restart with 20 eggs, which is definitely not enough for most forest/aztec levels.
Having said that, the game (PC version) is extremely well done and addictive, with an excellent difficulty curve & longevity: a must play!