Took about 15 minutes to get the BotD...while playing gears of war 2 as well. The game is just like advance wars so maybe I had an advantage having already played the heck out of this. It was fun!
Got 1000 in a few minutes with...average difficulty. Cursor just past the middle of the screen towards the top. The idea is to hit the enemies in front of you so you don't run into them. I upgraded all of my health, speed, jump about half way, then got double jump and got to 700ms. Upgrading my damage output and rated of fire helped a lot. It's possible with low amounts of upgrading. It's just practice. It's a good game and a nice challenge!