Plants vs Zombies first impressions

Popcap have released their newest casual venture Plants vs Zombies. Basically a simplified tower defense game with levels and really cute graphics. My first impression was, truthfully: "Wow! This is great! This is so much fun!". Yes, I committed the exclamation fan-boy crime.

My second impression, 20minutes later was: "What? Is this it? This isn't that much fun..."

The next time I had a conscious thought was an hour later. An hour of hard concentration trying to kill zombies. Have no doubts, this is a most excellent game. And I will get into detail on why I think this is shortly.

UPDATE:

Downloaded the demo on my girlfriends Mac, two hours later she'd bought the full game. Two days later she was stuck on one of the final levels of the game. She'd grinded the entire game. Yes, I'm proud of her!