On the achievement tab there are two buttons < + > It takes an annoying time to click through to look at what achievements you need to get and how to work towards them ( especially since new event ones appear at the end). As the title suggests there are a few ways to make this easier if you could consider having a scroll option that eases the transition, page numbers to click through multiple pages, stack the multiple achievements from the same tree i.e. monsters killed and or have a toggle option to see achieved/unachieved goals.

the shift and arrow, and the control shift arrow feature work in any code name entertainment 'flash' game and in and place there is a list of things to scroll through, either horizontal or vertical. always has since their first game in 2008 or thereabouts.

and I too love the idea of stacking common things, or having them grouped/collapsible/expandable like in Excel