New Inventory Functionality 

Equipped items are now stored in slots separate from your main inventory. These slots can be accessed by opening your inventory and hold 'E' on keyboard or 'RB' on game pad. This is to free up space in your inventory to carry more stuff.

Also, if you try to use an item and you cannot, you now get a message telling you why it didn't work. For example, if you try to use a Defence Upgrade and you have no defensive item equipped, it will tell you that.

Full Change log 

• Things are now unlocked at the end of a run, rather than during.
• New inventory functionality (see above).
• New HUD graphics for equipment.
• Two new items to unlock and discover.
• Fixed certain items ignoring the player level requirements.