Chapter three is currently in the testing phase. If all goes well, the new version will be live in a couple of days. It features a new area, new music theme, new boss, and a couple of new enemies. There are 18 new items/weapons as well, as you can see on the screenshot. And 3 new pets.
Overdose effect is removed from the random potion pool and now has a separate drink called Beer, dedicated to it. So you never get reversed controls by a random stroke of bad luck. Drink it twice and it reverses back to normal.
A new type of damage is introduced: Lightning, with two weapons to deal it. It has limited range, but can go through walls and multiple enemies.
Elemental damage like fire, ice and lightning can be upgraded with special items now. You can upgrade fire and lightning damage, and the freeze duration.