NOTE TO MODERATORS: THIS ONE IS DIFFERENT FROM MY OTHER POST, PLEASE DELETE THE OTHER ONE AND ADD THIS ONE INSTEAD BECAUSE THIS ONE HAS UPDATED INFORMATION
perhaps you can add strategy by making it so that you can see the other person's HP bar next to their names as well as how many of each weapons they have left (this latter one you can do by hovering your mouse over them).
and also make it so that more people can play on a single map or make the maps slightly bigger to incorporate more people.
include large patches of invincible bushes that can't be blown apart merely to obscure the view (you can shoot through the bushes and hide in them for strategy), or include foggy areas and such, include regenerating trees that can be blown apart and invincible rocks that can't be blown apart to block the view and shots and stuff like that, and make it so that tanks that have recently died are in flames for a short while that drain your HP when you touch them, or add in teleporters that teleport you from one teleport to another (of course if someone's guarding the teleport just kill him directly without going into the teleporter), or make pools of water that regenerate your HP/armor or even weapons/shield/front guard slowly (more on shield and front guard below)(guarding the pool strategy anyone?)
you should make a shield that regenerates very slowly by itself and have extra items that also boost your shield's capacity or instantly replenish shield. (you enter the game with 1/3 shield and u have to wait for your shield to charge up or whatever u choose.
front guard is a new system that allows for players to...with a certain amount of mana (more on mana below) put up an semi-invincible guard (can be broken if taken enough damage) on the front of their tank for a brief glimpse of a duration
also include a new system called mana/energy/plasma or whatever you'd like to call it (it takes mana to use grenades/mortars/front guard (mana also replenishes slowly over time). (you enter the game with 1/3 mana to limit the usage of grenades/mortars until your mana charges up or whatever u choose)
you should make tanks move slightly faster
maybe make it so that you can include a snipe/zoom function for the nuke or the mortar (this new function weapon allows you to zoom in, but it is hard to control because it shakes all over the place. for the mortar this would work by zooming to where you want to aim then launching the mortar).
i don't think you should put in a brief invincibility period after you respawn, because camping is always part of strategy.