>So Zapper, could you elaborate?

You already said the obvious:
- Item slots reduced to five, since we had the impression that the Clonk was able to carry too much and therefore never actually needed lorries etc. One idea was to reduce it even further (to three maybe?) so let's see how 5 works out first.

- Two-hand-control removed. We had the impression that, while adding a lot of interface clutter (who of you actually knew how to select an item into the second hand via keyboard?), it did not really have any benefits for gameplay with the only beneficial situation being shield+sword. You were more likely to just lose your items in your inventory ("on what slot did I put it again?") than use it efficiently. There is now a quick-switch-button ([Q]) as known from f.e. many shooters that switches back to your last-selected inventory slot. That still allows pretty fast shield+sword action while not being so very unintuitive like the two-hand-control in all other cases.
The right mouse button is currently what was [Shift]+[Click] before: throwing the item away as opposed to using it. Let's see how that plays out.

- Cycle through your inventory with the mouse-wheel. With only one hand, this well-known mechanism can be used without having to worry about which hand is cycled and why. Zoom is now on [Shift]+[Mouse-Wheel] since it usually plays a very small role compared to using your inventory - especially if more and more scenarios currently have a zoom-limit and you can't see the whole map anymore anyway.

Now the other points:

- "Lazy reactions". Clicking and holding the mouse-button now executes the action whenever possible. What does that mean?: Imagine you try to start aiming with your bow but are still in the kneel-down-action and therefore can not use any item right now. Currently, the action is lost. You never aim the bow and have to click the button again once standing. In the Controls-branch, the action is executed automatically when you are standing again, if you are still holding down the mouse-button. For scripters, this also reduces effort, since quite a few items had custom checks for re-aiming (shield/bow) if disturbed (by tumble/climbing). This is now handled by the Controls library.

- The action bar now only appears after holding down [Space] for about a second and is then displayed a lot more prominently on the screen. When only tapping [Space], the most fitting action (first on the action bar) is executed. In our test games this was what the player wanted 90% of the cases anyway (grabbing lorry/chest/building) and therefore there is no need with spamming the screen with an ever-changing bar at the bottom of the screen.

- The inventory bar is now displayed on the bottom of the screen, since the action-bar moved and made space ;)
This better reflects the layout analogies between the number keys and the item-slot that the key selects. Also, you don't have to look on the left side of the screen anymore (! which is probably a positive point, I suppose?) since the inventory-bar is now always centered.

- The inventory and object-interaction menus will be merged into one. This is work-in-progress. It should help both simplify the interaction for the user ("how did that work again??") and merge some of the dozens of different menus we have right now.

PS: And I also cleaned up the old Controls-library and split it into about three or four libraries just to be able to work with it.. :)