Nice game! Reached the 6th floor and died. Those dirty skeletons.
I'm pretty curious on how you made the weapon attack. In my little project I'm working on in the free time I've only made the weapon rotate around the player at a certain distance and don't know how to do the attack.
Also, amazing game!
Animation wise? Not entirely sure what you're asking about but you can download the .love file, unzip it (it's a zip really) and see the code. It's not very long.
I think you'll find all the answers in weapons/BaseWeapon.lua, weapons/Sword.lua, and player/Player.lua.
Don't worry even if you don't know lua, it's pretty much looks like pseudo-code :)