Actions in the game such as building, logging, mining, claiming and eating can have either lag or an animation that is slow to start and take variable amounts of time to complete. This is especially bad for eating, which can kind of be accelerated by clicking multiple times, but not immediately, leading to having to click many times; and also for claiming and un-claiming with the claim tool, which seems to take an almost random amount of time or simply not work on some clicks for unclear reasons.
Additionally, building and logging in particular involves very frustrating and annoying targeting (the click target for building the block where you want it may be an oblique side of another block, leading to frequent misclicks; logs that need to be split look visually almost identical to logs that can be picked up; click targets for logs are hard to find in brush or near obstacles; click targets for logs physically move in the world as the log is moved while it's being cut up; etc.)
Some work on the UX of these actions so that: it's clear when an action has begun, when the animation can be skipped, when it is ended; clicking on the next action just barely before the previous action is done smoothly queues the next action; targeting for building and logging is nicer in a general sort of way; and so forth would improve polish a lot.