By planting plants and defeating the zombies. Best tactic is to hold zombies off with the walnuts.
Kill all the zombies in each stage and beat the final boss
Beat the game
Beat level 5-4.
It is on level 4-10 when you play it a second time once you beat the game
Normally in the 2 first levels of plants vs. zombies the zombies are the newspaper zombie, zombie and zombies that are in costumes are in those levels.
Yes you do
Level 4-10
you just have to survive 20 waves of zombies.
no!
Get 30
Beat all levels from world 1-3. The fourth level can be unlocked buy a Time Key. If it's not yet unlocked, you may have to update or reinstall your copy of Plants vs Zombies.