* Sinfully ugly. Animations everywhere. Flashing. Stupid design decisions for placement of things. Even if you tell it "very fast" animations. And if you speed up the animations so you can play your turn better, you have an even harder time following what your opponents are doing.
* All but impossible to keep track of what your opponents are doing unless you really want to click the read log button every turn.
At normal speed I think there's plenty of time to see everything your opponents do. Fast is too fast to see what's going on. On very fast however the status line tells you what cards they gained, which is often all you care about, and when you specifically want to know something else there's the log.
* Sounds are terrible.
Well I wouldn't really know. As with all computer games I play, I turn the sounds off and listen to music. As we speak I am listening to That Time by Regina Spektor.
* The UI itself is atrocious.
I think the UI is fine. It has certain specific things that need to be improved, like Wishing Well, and other stuff that could be better, but overall it's fine. At one point it had serious issues but I don't think it does currently. I don't feel like I'm fighting the interface.
* Load times are unbearably long.
* Everything's slow too. When I click to "play treasures" for example, it takes multiple seconds to process.
This could be some combination of, your OS isn't supported yet, your browser isn't supported yet, your internet connection is slow, or you have been on at times when they had server issues. When it's working, with my browser/OS/connection, it plays at a reasonable speed, except for the case of "click on multiple cards" things like Chapel, where it should buffer the set of choices and send them at once.
* No one-player "try things out" option? (Ie, single-seat tables).
I thought there was. I'm not checking.
* Multiplayer "play now" just joins you to the first table, rather than you having a preference of how big a table you want.
* Multiplayer really pushes 6 seat games. Dominion is terrible with that many players; it should default to the real value: 4.
I wouldn't say "really pushes" so much as "allows." There are not many 6-player games being played, so if you insist that it pushes them, man, it is ineffectual at it. It's fair to say that the default shouldn't be 6; if we went by, what will most people be playing, it should be 2.
* Multiplayer lobby is pretty damned fat and ugly. No sorting, filtering...
* This might be because I'm a guest -- is there no option to have the cards NOT show up until the game starts? Blind games are necessary.
* Apparently no restricting of generated kingdoms (why the hell did Goko rename them to "decks" instead of kingdoms?) by sets.
* Or any randomizing by any OTHER criteria ("must include at least 1 reaction" etc).
Better matching, and ways to muck with the set-of-10 without picking the specific cards, are features I expect to show up eventually.