The content felt repetitive and the upgrades felt flimsy. I feel like this game would benefit from a more traditional progression system in which you could upgrade particular aspects of the tank itself (pay X amount of credits for Y upgrade).
Another issue I encountered was the useless nature of teams. My teammates did indeed eat bullets for me and shot the opposition but were also stealing my kills and felt like they were nothing more than just bullet sponges to keep around in case I start getting fired at. Give me a good reason to want to roll in packs; Point bonuses, synergetic effects,not stealing kills, being able to lead them instead of following their asinine trail. Which leads me to my next point,warlord mode.
The Warlord mode is just a color filter and a high score. I see no purpose to it whatsoever beyond that. An alternative to this could be that when one becomes a warlord your teammates will start following you if you were to press a certain key. I would see this as a great incentive. Another small note is put enemy warlords as bosses on the map. Make them giant historical tanks (look up the Ratte or the MAUS for examples) that serve as a challenge/monetary system (if you implement one)
Just an idea to pose to you, some shifts in game play would be nice. Consider using Terrain such asmud,hills, snow to change vehicle handling/speed and also add in some cover or even bushes for players to hide in. I think it would be neat to add the ability to wait in a bush then BLAM! right in the enemies face!
As a concluding point I will say that this game does have potential but needs far more development; 2 and a half stars for a half-way done project. Add more complexity and depth to the game and moreover a less linear gameplay experience.