Items and weapon upgrade materials ( those items that their name starts with something ) are stored in pack.
Bootlickers have a nasty trick, they make you unable to move for a short time. Pretty deadly if you are in middle of a fight.
Each weapon has a challenge. First prize of the challenge is always a secret skill for that weapon. This is the challenge for a weapon called Brusher's pike.
When you get low on health, the game gives a warning about it. Also notice Galleon mortar, a powerful weapon with a great range.
Here is the Arsenal. A place which you can choose and change your weapon and special skill. Also when you are in the middle of a mission, going into arsenal will fully restore your consumables.
Here is the forge. A place which you can upgrade your weapons with upgrade materials. Weapons with red star on them are fully upgraded.
This is distillery. A place which you can put spirits in unlocked slots and take advantage of their special bonuses.
Memorial. A place which gives you challenges and when you complete them , you'll get fragments ( currency in Bastion ) as a reward.