With Survival Mode, you get mobs. While it is limited to sheep and zombies for now, it’s still something to fend off. It seems that more mobs will be added in the future. Monsters will come at you in the night, so prepare yourself.
In the 0.2.0 update, you can now choose between Creative or Survival Mode when creating a new map. While the previous version had a limited selection of blocks to use, there are now more blocks; notably, doors, fences, and gates. Now, you can also gather resources. You know, all that necessary stuff that was missing in the first version.
Another neat thing is the addition of flying to Creative Mode. Yeah, now you can fly (not in real life, of course)! Pretty neat stuff, right?
The full change log:
Major version 0.2.0 (first survival update)
+ New mode! Choose between Survival and Creative mode when creating a map
+ New blocks; most notably doors, fences and fence gates
+ Added flying to Creative mode (double tap jump)
+ Added mobs; sheep and zombies being the first
+ Day and night in Survival mode, with monsters coming at night…
+ Gather resources from nature!
+ Tools for different purposes (digging, attacking.. shearing :))
This is a rather important update for Minecraft – Pocket Edition, so I recommend that you go update your game now.