Lots of people don't understand what "pre-alpha" means. Spoilers: It means that things are not in a final state.
For example, complaining about the UI? If you looked at how the UI evolved from the announcement of Original Sin 1 to the final, you probably notice that the UI changes. Because that's what happens when something is in development.
Complaining about the game being "too colorful" is just plain stupid, full stop.
Complaining that combat with level 1 characters doesn't show off higher level stuff like level 5 Counterspells or level 5 Uncanny Dodge is also silly.