A game with a simplistic 5 lines of incoming zombies and a garden to plant you seeds - with some complexity mixed on it
It has a simple design, it is like a tower defense game. You get to complete the campaign in a somewhat quick way. At each level you gain a new plant. There are dozens of them, each with specific tasks. Some shot, some double-shot, some triple-shot, some gather sun (the game's resource), some freeze, some slow, some smash, some set on fire, some block, some confuse, etc...
The interesting part of the game is not so much the campaign, where you get started, but after it. It is something that must be mentioned, because in a game usually it might die after the campaign. On this one, you still have mini-games, challenges, survival mode (for hardcores - trying to reach as far as possible), zen garden, etc. All with rewards (new plants, chocolates or money) so that you can for instance buy new upgrades for your plants or products to treat your garden.
If you put aside the fact that this is not a "100%" professional game (I mean, it is, but you get what I try to do - you can't compare this to other kind of games to some extend), you will find that it is still a rewarding, fun and immersive experience that will kill hours of your time.