Disney Infinity 3.0
31 Achievements
14-18h
PS3
Shell Collector
Have 250 shells in your collection at one time
4.7%
How to unlock the Shell Collector achievement in Disney Infinity 3.0 - Definitive Guide
DISCOKING
This will come naturally while playing the story. There are literally thousands of shells all over so you will easily get this trophy while playing your first level in the story mode. I don't think you could avoid this trophy even if you purposefully tried to avoid the shells. Furthermore, there is a clam shell house you can purchase and build in Morro Bay that pumps out shells for you -- not that you will need it though.
Darth, Grif55
Shells are the in-game currency, as long as you don't spend any shells you should get this achievement early on. You will have almost half of the needed amount by the end of the first level.