http://i63.photobucket.com/albums/h133/franpa/Untitled-79.png

At the moment, a selected item on a menu has a orange colour background, this might not be very obvious to players so I have this simple suggestion. As you can see, adding such an icon makes it exceedingly obvious which items you have selected!

Also when you reach a elevator before a Tier that you do not meet the requirements for (EG: 8th floor), when you take the elevator the game shows what items everyone picked up during the adventure. During this screen the red X in the top right corner of the dialog should be replaced with a green Tick, as a Green Tick better represents a "Click here to continue" function while the red X looks more like it would kick you back to Haven if you don't wait the 60 second count down.

Obviously my picture is a crude example made in MSPAINT but it gets the point across and I'm sure you can make a better icon that fits the smaller parts of the menu!