What If? Comics Greatest World was neatly set up in one big annual that felt like it was worth the money? We'll press on after you're done googling failed publishing initiatives.
If you haven't read Geiger before, this book is a perfectly fine jumping on point, although it is like any other anthology in that it's a mixed bag filled with a wide range of creative styles. It does manage to present an entire comics universe existing in an irradiated Las Vegas in just 80 pages without any story over-staying it's welcome. Highly recommended for fans of Geoff Johns, anyone who's ever wondered what the Cursed Earth would look like without any Judges, and those who like to roll the dice on first appearances. Take the gamble and check it out, maybe get that new pair of shoes for that special somebody, like your Mom.