In terms of what Queslar is, it is an idle game which can be played in your browser which has trading with other players attached to it.
General idea is to battle mobs to get stronger, to fighter harder mobs,
upgrade your own stats.
Get equipment from other players/general shop (not worth doing any more, just use marketplace)
Group together with other players in a village to further upgrade stats.

Here's a screenshot of other games forum where i've underlined all the Queslar topics:

Cheers all