Okay, I've played a fairly decent amount of games on Goko at this point, so time to reflect on its UI.
Let me start by saying: It's not thát bad and the issues I have can be fixed quite simply.
The problems I have resolve around a couple of key issues:
1. It doesn't protect against accidental double clicks.
This is by far the biggest problem.
Let's say Swindler is your last action card, you play it and you're opponent trashes a Copper, hooray! Excited, you click on Curse, but you accidentally double clicked, entered the buy phase and bought yourself a Curse as well. This is bad, horrible even, maybe you had $8 for a Province!
The positioning of the buttons is also very awkward. The "End Turn" button appears in the same place as "End Actions". So let's say you had an action card you didn't want to play, click End Actions, accidental double click and you bought nothing!
There are some other buttons awkwardly placed like that.
Accidental single clicking is also an issue, especially when you use a touchpad instead of a mouse, but I don't have that much problems with it. Usually I pick the right cards.
2. Dragging and dropping is finicky
Choosing between putting something on your deck and discarding it is a real hassle. The positions of the decks are so small and you have to watch for little green arrows to appear to make sure you've got the right one. With Watchtower you have to move your mouse all the way to the trash. Why not have a couple of buttons "Discard, Put On Top, Trash" or something?
3. It doesn't prevent stupidity, because it wasn't clear what was resolving
Okay, this might be more of a human problem since you just have to pay attention, but I can recall a couple of times where I've thought I wasn't trashing anymore and ended up trashing some good cards. Or when I thought I clicked "Done Discarding" when I hadn't. Hamlet and Storeroom are notable culprits as you get to discard twice. I've also had turns where I thought it was my turn and there was still an opponent's Bishop waiting for me to trash something.
4. It moves cards in your hand after you've revealed them
This is more of an annoyance, but say you're Moat is to the left or in the middle, after you revealed it once, it's shuffled over to the right. So you can't click the same location to reveal it the second time.
5. The chat window
I hate how this thing keeps popping up all the time, just have a "+1" icon or something similar layed over the button to open the chat. And I hate how it's over the Continue button at the end of the game.
How to fix these issues? Well, most can be fixed by providing some sort of undo option when that's possible and doesn't have any strategic impact. Like, you never want to allow undo-ing playing actions, but you might allow a player to undo playing his treasures for Mint and Grand Market etc.
Another is to just add little improvements to the positioning of some elements to make it less accident-prone. Having the End Actions/End Turn buttons in the same place is a bad idea. Or when you're doing something to a lot of cards at once (trashing, discarding), add them to a little box (like the "Reveal" box) first, click "Done" and only then discard or trash them.
What do you guys think?