DEAD RISING 2: CASE ZERO

This is a rather simple achievement to get. All you have to do is kill 100 zombies. The wrench or Crowbar are good weapons, especially if you find the book which powers them up. Combo weapons will give you more experience for each kill. The simplest way to kill them is with the trolley after case 0-2.

You'll likely get 100 kills without really trying, but if you want to get this quickly at the beginning of the game, do the following (spoilers below):

Your first task in the game is to find some Zombrex. You'll be guided to an ambulance with the Zombrex inside and once the cutscene is over, you'll have a trolley with a part-built motorcycle inside it.

This cart is pretty much the only indestructable weapon in the game, so make your way back to the safe house, using it to run over as many zombies as you can. Knocking a zombie down often won't kill them, but running over a downed zombie usually will, so try picking a crowded spot and run in circles until you've run everybody over.

This technique also works well for getting 1,000 kills.

Simply kill zombies as you go, The combo weapon Spiked Bat (baseball bat + box of nails) is your best bet for this, as it's fairly durable and very damaging, with an entertaining alternative attack.