Update 0.40 - The Skill Tree Overhaul:
@Loot & Equipment:
Added new element; Shadow
Added new stats; Shadow Damage, Shadow Resistance, Cooldown Reduction, Mana Cost Reduction, Critical Strike Damage, Companion Health, Companion Damage
Added new enchants/affixes for all new stats (7 total)
Added possibilty to click on the item name tags to pick them up when using the "inspect all" feature. With click to move your character will walk towards it, otherwise you still have to be pretty close to it on the ground.
Added options for the "inspect all" feature, can now toggle the minimum quality to find and if it should ignore items locked to other classes (gameplay options menu)
Many legendary and unique items have had their class restrictions removed
Some base helmets such as hoods have had their class restrictions removed
Potions drop much less frequently from regular monsters
Class restricted items no longer roll elemental damage to unused elements of that class
Reduced drop rate of Unique and Legendary items from regular monsters by a lot, but increased the bonus rate granted from champion and elite kills by a lot, too
Bosses and chests have a much higher rate of dropping high quality items now
The most rare chests no longer require keys to open
Reduced mana gained from mana potions
Some Unique & Legendary (and set) items have been redesigned to fit the new skills. More to come!
Some Unique & Legendary items have had their effects temporarily removed as they have become obsolete, and will have new ones added later
Burn/Poison/Bleed enchant texts clarified
Added 32 new legendary items fitted in 8 new item sets!
Berserker sets:
@Punisher's Tools (lightning - helm, armor, weapon, accessory)
@Power of the Frostborn (frost - helm, armor, weapon, accessory)
Templar sets:
@Cain's Battlegear (fire - helm, armor, weapon, accessory)
@Titan's Armor (physical - helm, armor, weapon, accessory)
Warden sets:
@Nature's Vengeance (poison - helm, armor, weapon, accessory)
@Winter's Touch (frost - helm, armor, weapon, accessory)
Warlock sets:
@Corruptor's Plague (poison - helm, armor, weapon, accessory)
@Death's Embrace (shadow - helm, armor, weapon, accessory)
@Stats:
Attack speed no longer reduces cooldowns of skills
Mana and Health steal effects have been nerfed
Mana and Health regeneration has been lowered
Removed Stamina stat, and removed it from items and affixes (old items may still show it, but it will do nothing)
Increased the bonus magic and crystal finding rates on high difficulties
Reduced the mana stat rolled on items
Electric element is now called Lightning element
Elemental Power is now called Elemental Damage
@Skills:
Removed and/or redesigned old skills, and added over 150 new, totalling just over 200 unique skills available, around 50 for each class! (previously there were 60 in total, 15 per class)
Added a 6th skill slot! Default keybinding is [4] for keyboard, and (X) for gamepad
Skills are now available at levels 1/5/10/20/30/40
Poison damage over time effect and bleed effect now ticks 4 times per second
Burn damage over time effects now ticks 6 times per second
Made it possible for effects to be triggered from critical hits (eg "chance on crit to do X")
Non triggering effects (eg damage over time or very rapid effects that does not trigger "on hit" skills/enchants) no longer cause hurt sounds and hit sounds to be played
Damage over time effects, thorns, and some other effects no longer cause gibbing
Damage over time effects no longer cause screen shakes when critting
Skill information will now consider stats such as cooldown reduction and mana cost reduction when presenting values in the skill tree information
Skills now display exact damage numbers in addition to a damage percentage. This can be turned off from the Video & Interface options menu if you prefer
@Sound:
Added new sound effects:
@Entering/exiting forest areas, unstable dimensions, and challenges
@Spike traps
@Gibbing flesh monsters (eg no skeleton or treant gib sounds yet)
@Shrines
@The new skills
@Interface:
Damage number colors are now based on the element of the attack. Players getting hurt is still in red for clarity (may change)
"Inspect all" tags now highlights on mouseover, and the lines are a bit more clear
Updated difficulty screen information with detailed information
The skill slots on the HUD no longer draw the associated button for skills that cannot be activated, such as companions and auras
Updated some fonts for readability
Changed color of Physical damage "element" text and skill outline
Updated keybindings menu text to reflect how skills now can be bound to any slot
Put new experience bar where Stamina bar was
Passive skills are now circular, and buff/aura/companion active skills are octagons
Keyboard keys that are either letters or digits are now presented in brackets to be more clear (especially in the skill tree where the skill ranks were also present)
Added new interface options to disable damage over time numbers and/or only show critical hits
@Enemies:
Removed the extra elemental resistances granted on high difficultes for enemies, but instead increased their health by a lot!
Monster multiplayer health bonus increased to 50% per player, up from 30% per player
Changed some bosses attacks to be more interesting and fitting
@Visuals:
Updated burn and poison particles
Improved visuals of ground burning effects such as the effect left from Molten Shield
Spiders and Beholders now have different colored blood and gibs
Players can now become gibbed like monsters
Blood bolts and similar monster skills have had their visuals updated
Various monster & champion skills have had their visual effects improved
New aura visuals
New chill & poison visual effect
Added a basic system for "hit effects", eg an enemy taking lightning damage will appear electrocuted for a short duration. Only works for electric damage currently
Lightning orb colors updated
New portal colors for challenge areas and unstable dimensions
@Gamepads:
Damage over time effects like poisons now cause much smaller vibrations on gamepads
Added a new sub menu in the controls menu with the following options for each player:
@Vibration strength
@Left stick sensitivity
@Right stick sensitivity
@Aim in walking direction (single stick usage)
@Smooth walking (walking speed depending on how far you pull stick)
@Misc:
Added new killstreak effects to 500, 1000, and 1500 streaks. Changed old ones a bit
Added a key binding for forced attacks when using click to move (eg hold this key [default Shift] to force attacks when clicking)
Added experimental support for odd aspect ratios and ultra-wide screens
Can now change names of characters from the Load screen
Updated the requirements for some stat-based achievements (eg +magic find achievement ignores the difficulty bonus)
Improved pathfinding for companions when they follow you
The Waypoint in The Lower Temple halls now spawns near the entrance
@Fixes:
Fixed "inspect all" tags overlapping or having extra space around them depending on settings
Fixed using gamepad and summoning/casting spells outside of the view, they should now land just on the edge of it
Fixed chests spawning infront of entrances in forest areas
Fixed Spider Cavern potentially generating unreachable areas
Fixed bug where belts weren't properly updated and would sometimes bind non-bindable items such as equipment to belt slots
Possible fix for people experiencing a fully persistent game world across saves
Fixed HUD not being updated after swapping gamepad / keyboard controls ingame
Fixed HUD sometimes not being updated after performing changes to belt slots in the inventory
Fixed companions and enemies sometimes locking their aim to the right
Fixed companions' and enemies' spells sometimes dealing physical damage instead of the correct element
Fixed the default death sound being played over monsters actually having their own death sounds
Fixed many fire skills having the wrong color on their light effects (was red, should now be more fiery)
Fixed issue with some buffs and effects not having the intended effect due to the order in which they were calculated
Fixed item-granted skills unbinding after loading a new zone if said skill had 0 points spent in it
Fixed Spiderlings having massive hitboxes
Fixed Pixies having too small hitboxes 
Fixed transparency issues with inventory and skill tree menus
Fixed some timing issues with very high attack speeds
Fixed numbers being presented with decimals where unnecessary (eg 10.0 is now just 10)
Fixed most damage over time time effects dealing too much damage, they were doing the intended total damage each second instead for the entire duration
Fixed issue with targeting not finding the correct position to place spells
Fixed buffs and debuffs being removed before performing their last planned "tick"
Fixed notices like "immune" not popping up
Fixed issue with immoblize effects not fully immobilizing foes
Fixed skills not being properly performed even if animation plays when having very fast attack speed
Fixed critical hit damage being incorrectly calculated in some cases
Fixed critical hit damage on items granting 100x the listed amount (whoops)
Fixed stat comparison values sometimes being drawn without parentheses or without + and - signs
Critical hits are now properly calculated BEFORE applying effects like burns and such, making the damage scale correctly
Skill reset elixir now properly plays potion drinking sound when used
Fixed killstreak "Carnage" effect fireballs not moving
Fixed some general "chance to cast X" legendary items casting incorrect spells or just doing plain weird stuff
Fixed achievement "Perfect Score" not always triggering
Fixed killcount timer increasing when friendly non-player characters died (summons, companions, etc)
Fixed some typos in advanced stats screen
Fixed unbinding/binding skills not triggering correct stat/effect checks/updates
Fixed crash when gambling for items that are of a different class
Fixed an exploit allowing duplication and unlimited stacking of items
Fixed slowing animation appearing from Shield Throw skill
Fixed getting stuck in wall when spawning the boss in Shrine of Ayeela
Fixed boss not correctly spawning when using Waypoint to access Shrine of Ayeela
Fixed item "Ayeela's Guard" (a shield) looking like a helmet
Fixed attack speed being incorrect when not having a weapon equipped
Fixed the skill bar sometimes going transparent
Fixed there being holes under the large trees of Act 2
Fixed Elven Rangers using Vineshot to get you stuck behind trees in Act 2
Fixed delay on death voice for High Priest