Weapon Upgrades are only given out at the end of Levels 1, 3, 4, and 6. You will not get a weapon powerup in a level unless you die, and need to get the weapon back.
Health and Shield Powerups These will appear after you've been damaged, and at fairly generous intervals.
Extra Lives Extra Lives will rarely appear in any level, at any time.
Total War BattlesMore guides, cheats and FAQS