From IvanWiki

• fluids can now cover items and characters and interact with them
• items made of iron alloys can now rust
• added directional light and day and night which use it
• added some cosmetical weather effects
• New Attnam has now many new NPCs, for instance a sumo wrestler who can be challenged
• polymorph control is now more interesting; you need to see a monster once before you can polymorph into it, and more powerful ones require more intelligence
• added wands of acid rain, mirroring and necromancy
• added scrolls of detect material, harden material and golem creation
• added several new monsters, eg. powerful named archangels for each god and necromancers who raise skeletons and zombies to do their bidding
• one can now give pets tactical commands, change their equipment and use them to carry extra stuff (these are accessed using 'C'hat and 'I'ssue commands keys)
• the player can now panic if he gets hit too much, like the monsters have done in previous versions
• the player can now become exhausted if he fights for too long and/or uses the new r'u'n command too much
• spiders are now able to make webs
• you can now get stuck to slime
• badly hurt/trapped bodyparts now become unusable until they regain some HP/become untrapped
• it is now possible to browse detailed death reasons of individual monsters in the postgame massacre lists
• added many new informative graphical details, for instance recently altered attributes are shown with a *different color for some time
• gloomy cave is now longer and has more special levels and rooms
• all the endgame battles are more complex
• added leprosy, a nasty disease which causes your limbs to drop off randomly