this ganme was nice.must do first is always damage upgrade to max and then thehealth upgrade.Speed was not an issue because there was always a speed powerup at hand. what was hard for me and I still couldn't pass was the last boss in level 21. I hit the tail, a mine came off, blow up .,.I lost health for being near but robo didn't.Now after about 15 mins. in to this fight(and i had full life and there was plenty of worms and one health powerup and no more enemies) I still could not kill him. I hit his tail for 8 times and he did not get shorter? A glitch maybe..who know. Also never save your points to levl you power later. you use once and you lose all your points. Over all..very fun to play. A little tip, skimming the ground is the best way to win without losing health points. Happy hunting!