What Can Make An Online Interface Difficult To Use. All those make it difficult for users to read at all. One way of determining that is asking How will consumers use my interface.

Dont add things to be clever or feed an ego is how you can sum up the second principle of good user interface. The main problem why the online interface difficult to use is because of the design. Hard-To-Use Interfaces Considered Beneficial Some of the Time Researchers in HCI share a common understanding that easy-to-use easy-to-learn and intuitive interfaces are beneficial to users.
Theres a reason for that.
Online interface design should be simple and user friendly. From this perspective a difficult-to-use interface simply adds an extra skill differentiator by which players can improve themselves. You should specify the operations you want anything that implements your interface to support. You must know how your online learners are going to actually use the interface.