I, Zombie
12 Achievements
1,000
2-3h
Ultimate zombie leader
Collect 90 stars
100
11.7%
How to unlock the Ultimate zombie leader achievement in I, Zombie - Definitive Guide
For the remaining levels, 3 stars is based on how quickly you finish the level. You can see the criteria when you finish a level. Nevertheless, it would benefit you to try and finish each level as quickly as possible so you have less work to do for the speedrun achievements.
The hardest part for me was getting all of your zombies to survive running past turrets. Watch the video closely to follow positions and movements for a greater chance at success.
Credit to TemporalWizard at xbox achievements for the Road Map, Silent Mugger for the Summer Level Walkthrough, and ProDivision for the Winter Levels.
*It seems like the Summer and Winter levels have potentially varying amounts of people/zombies on some levels - the video strategies remain sound with a small caveat for the final Winter level. On the final Winter level, your last attack is against a group of soldiers circling civilians. The video shows 6 soldiers circling, but the game only has 4. I found more success when I hid my existing zombie horde behind the house and occasionally popped out so the soldiers saw me. I kept popping out and running away until the 4 soldiers were grouped into 2 groups of 2 (other configurations killed my horde too fast). Wait until one group is by the corner closest to you and blitz with your horde and hope for the best. Good luck!
This is the hardest trophy in the game due to the requirements for some of the stars. There are a total of 30 levels in the games (20 summer and 10 winter) with each of them having 3 stars that you can earn by meeting certain requirements for each one. Most of them are for finishing the level with a certain amount of zombies left alive (or dead I guess) with a few of them for completing the level within a certain time frame.
For the ones with zombie's left requirements, take your time and be patient so that you can make sure your zombies survive.
For the time requirement ones, just focus on getting through as quickly as possible and don't worry about how many of your zombies die.
You must get 3 stars on all of the levels in order to get the 90 required for this trophy. You can see how many stars you have on each level from the level select screen, so if you are missing stars on a certain one, then just select and retry it until you get its 3 stars. Once you get your 90th star, the trophy will pop.
You must get 3 stars on all 30 levels to earn 90 stars. If you need some help getting 3 stars on a level, take a look at the following videos:
Summer Levels
Thanks to SilentMugger for the video.
Winter Levels
Thanks to ProDivision for the video.