Mortars is a LieroX game mode, with one-hit-kill slow-moving weapon, which you can shoot in a valley of 5 rounds, because of the game engine weapon switching 'feature'. Then you run away to reload, which happens automatically, but takes time.
This game mode was ofren derided by LieroX 'pro' community as noobish and lacking finesse of 'classic' mode, where you have 5 different weapons instead of 5 Mortars, and need to select the best weapon for each moment of the game.
But it was fun while it lasted.
https://youtu.be/30jw1_6rH4o
https://youtu.be/Q2ZAN9EGpCc - 'pro' Mortars match, which is mostly spamming the shots across the map, trying to guess the opponent position using that tiny minimap in the corner, and of course whining in the chat.