Moving on up
This solution will help you get to player level 30, of course like any free Micro-transaction game spending money will get this game done the fastest possible way. I am here to help you get this most time consuming achievement the fastest possible.
If you want to save time and spend the minimum amount of real money, you can spend 5$ and take the diamonds you get from the 5$ diamond pack and get 1 7-day Gold VIP Cube which will give you a great boost in Xp. Then take even more and get XP boost Cubes. Doing quests while Silver VIP will also net you diamonds and you can put towards XP boost cubes or more 7 day trials to maximize your XP if you do not finish in 7 days. Doing this will minimize your matches to about 300 to get the achievement.
Now for people who don't want to spend ANY MONEY im sorry but it will take you about 500 matches but of course I will tell you the fastest method without spending money. (You cannot get to Gold VIP without becomming Silver VIP and the ONLY WAY to get silver VIP is by spending money, of course they would do that).
The Method:
Fastest match I have ever had: 45 seconds
Needed:
Assassin (Unit)
Bucky's (Ultimate bucky's are better)
There are so many variables to doing this, 1v1 im afraid is not possible with this method as the enemy base has a lot of defense. It can be done 2v2 and 3v3, in 2v2 my fastest time was 56 seconds, 3v3 was 45 seconds.
Right in the beginning of the match build 2 groups of 4 assassins and drop them on the ground with left on the d-pad, then drop 6 bucky's each person ( Ultimate bucky's are best ). Once you do those, build 4 assassins each and fill up your airmech's with them, once filled with the assassins, Que up 5 more to be ready for the next pick-up. Do all of this before the timer runs out.
Now right when the timer runs out immediately all 3 airmech's run to the enemy base, drop off right behind the base your assassins and fly to either the newly captured base or the base on top of the map to get the new group of assassins and refill on energy/health. Drop those assassins off and do one last run, doing this run if you hit the Y button you will build more Assassins ready to go when flying to the enemies base or back to your base. After this drop just join in on destroying the base. Yes... you will finish easily in UNDER A MINUTE.
Tip: Some good things to help you get this done easier are Ultimate Samson, Regular Samson, Experimental Fuel item, Blueprinted Turbines, Advanced Engine, Efficiency Chip, Lightweight Chassis, Paladin Airmech, Neo Airmech, Helix Airmech.
Me and a couple of buddies have continually tried a multitude of methods trying to beat this 45 seconds. All have failed, this is the fastest.
Any questions or comments? Message or comment. Have fun and good luck!