To get this, you simply need to complete the game while collecting less then 40% of items. While this sounds like it would be hard, it's not all that bad.
My completion stats on Hard:
3/20 weapons
14/16 tools
8.4/13 Health upgrades
5.5/9 Power Upgrades
1 Size Node
1 Range Node
2 Notes
This put me at 34% and gave me more than enough to beat the game on Hard. You can take a look at your collection % when you look at the save file before you load it up and start playing.