PLANTS VS ZOMBIES / Popcap / Android
Popcap's whole deal has always been plumbing the back catalog of gaming history and re-packaging ideas for the "casual" market. Instead of directly "repurposing" a specific game this time, however, it's more like a distillation of the RTS and "tower defense" genres into a simpler, cuter format that's more accessible to soccer moms and travelling businesspeople.
The premise of Plants vs Zombies is that you're an unnamed suburbanite defending their house against waves of zombies, by way of a huge assortment of magical plants with various offensive and defensive powers. It's simplified down to a 5 x 8 grid, with your house at the far left. The zombie hordes always enter from the right, and the plants generally attack only to the immediate right of where they're planted in a straight line. The currency needed to plant is sunlight, which sporadically drops from the sky, but sunflowers can also be planted which act as your little peon generators as well.
The game is divided into five sets of ten levels each, which each have a bit of an environmental twist. The first ten levels are the most straightforward, as you defend your front lawn during the day. The second set of ten takes place at night, however, which removes the random drops of sunlight, but allows you to grow a range of mushrooms that somehow generate sunlight and also provide free firepower. The next two sets of ten move to the backyard, adding the twist of a pool taking up the middle of the playfield, before moving on to the roof for the final set of levels.
There initially seems to be a fair amount of complexity with the sheer amount of plant types that gradually become available, but after playing the first 20-30 levels you realize that the game isn't very challenging. The same basic strategies can be used over and over with little tweaking to account for the new zombie types.
As an introduction to strategy for a newer gamer, it's a pretty good choice. It's simple, polished and has a smooth interface, but enough depth to not bore them. As with most of the casual market, however, it's a little too weak and watered-down to last long for the more serious/long-time gamer.