This game is great and I'm really enjoying it. I only sorta use the guides. I'd rather plunder through myself and figure it out. I've gotten 2 of the special plants and have 31 bugs so far.

My question is:
What's the difference between easy, normal and hard???

One thing I've found that helps catching bugs is having the plants that are flowering on the bottom row. Then the bugs have to fly down and it gives you a little more time to snatch 'em up.