So, I played the original Avernum series back in the early oughts, but never finished it (some combination of save file corruption, poor note taking to know what I still had to do, and lack of time). Seeing it on sale reminded me I've been planning to come back to it, and I figured the updated UI (and quest tracking system) would maybe help me actually finish the game...
Unfortunately, compared to the original UI, there are some serious usability issues, which have me considering if I want to actually play the game, or request a refund before the 2 hours/2 weeks is up (current plan is to see if they're resolved in Avernum 2 or Avernum 3, and decide from there). Anyway, whatever I decide, I figured it would be worth posting my feedback where maybe Jeff will see it; maybe it'll improve the Avernum 4 remake if it ever happens.
There are 2 major issues I encountered (and one annoyance), both before getting out of the tutorial area.
The first is the game is not playable without a mouse. In the original game, you could do nearly *everything* with just the keyboard, and the UI was excellent. Walk into a chest to open it, 'L' (or was it 'E' for examine...) key to look in a chest if any party member was next to it, 'L' key to get a description of anything further away, 'T' key to try to talk to something. The keyboard-only stuff works decently well for combat, but the world exploration phase will drive me crazy if I have to touch the rat. On that note, the remaining key binds are nonsense. If you have one hand on the rat (presumably your right hand), some shortcut keys are now out of reach of your left hand (mage and priest spells, for example). By itself, this issue is... annoying, but not the end of the world.
The second issue is much more serious. If you are running a fast, nimble, frail party, you rely on careful, exact positioning of party members in combat. This means things like carefully lining up at the edge of vision range to fire your first salvo, letting you get a second salvo before enemies close to measure. And here's the problem. There is NO indication of what your actual range is. There is NO warning when one of your spellcasters will run forward, nor how far they will run, in order to get their spell off. In the original game, targets out of range of a spell or attack would not be given a target label, allowing you to reposition and try again. In games like Shadowrun Returns, a line is drawn indicating where the character will move to before shooting, letting you either go with it, or manually order a more sensible move than running out of cover. Instead, what do we get? Nothing. I don't have any multitarget spells yet, so I don't know if a single too far away target will cause this running, but it doesn't really matter...
As for the annoyance, in-combat waiting has been removed. You can skip a character's turn, but you can't have them wait for a target. This means your front line fighters will generally skip their first turn, which is annoying. In the original, you could have your characters act in any order you wanted, by letting the enemy go first, and then using the wait command if the characters tried to act in the wrong order.
All in all, there are some improvements over the original Avernum games (like the new skill tree, new graphics, actual tutorial, and so on), but the gameplay itself is simplified in a bad way.
Edit: After a bit more poking, the 'U' key will let you select an item for "use", which includes opening doors and the like. It is neither listed in the help menu, nor does it have a UI element dedicated to it. I found it by "simply" trying every key on the keyboard. That still leaves the combat auto-movement, which is honestly the more serious issue anyway...