“Horizontally oriented inventory uses better screen space of nowadays 16:9 monitors. This layout reduce necessity to scroll through inventory to minimum and doesn’t obscure view on players character and its surroundings. Player has better overview of items he posses and time for all management of loot is significantly reduced.
Inventory is fully modular so it fits even on 4:3 and offers future possibility to be even organizable by players themselves. All slot sizes are same through whole UI so player is always sure whether item fits in slot or not. Player can choose whether he wants to have avatar panel on left or right side of the screen and can also organize order of containers.” Jan Tomasik