A seemingly simple game that grows on you and provides many more hours of fun after the main adventure.
The game takes a while to rise in difficulty but the excitement of encountering new enemies and finding new plants to use against them keeps the player coming back for more. The stages vary as well, adding new challenges and forcing players to adapt to new plants, or get swamped when caught unprepared by new zombies charging in through new terrain like a pool in the backyard or run out of sunlight (the game's currency) by not using 'free' night plants.
There are many different modes of play as well, like 'bowling' or puzzle games that appear both in the main game as well as in the mini-games mode and puzzle mode. There is also a survival mode and even games that go on endlessly, increasing in difficulty until the zombies finally break through and eat 'your brains'. All these provides hours of fun after completing the main game, and even then, the main game can be tackled again with a slight increase in challenge.
With plants to 'buy' and unlock, humorous introduction of the plants and zombies if you bother to look at the encyclopedia, secrets and cheats to modify the outer appearance of the zombies (unlocked through the Tree of Wisdom), there is a lot packed into this cheap and undemanding game (I ran this game on my net book).