Usability Tweaks

The biggest addition in this update is the realtime view of important key and mouse actions. This should make it a lot clearer what can be done and how.

Machines will now emit two new warnings:

• when you feed it a resource that is not in the recipe
• when you feed multiple valid resources from a recipe on a single input

Added two shortkeys:

• A shortkey to build ghosted items in your selection (B)
• A shortkey to open the help menu (H)

Two tiny UI tweaks:

• Added an "X" to the top right of explainer popups, just in case it is not evident how they are closed.
• Moved some of the buttons in the top menu to the right and added a label