This game is such a blatant copy of a Korean game called "Fortress (포트리스)". The map and even the tanks are the same. The map here is the copy of this original map: http://blogfile.paran.com/BLOG_480401/200611/1163224848_20061110110040_116316724007115.gif
If you want to see more evidence, just google image search: "포트리스 벨리"
Please thumbs up to keep this comment up and fight plagarism.
For those who are whining about getting only $1,000~2,000 per run, here's how to get $20,000+ easily:
1. Fully upgrade wheel and rocket
2. Get Superman
3. Get Bat
4. Get Pole Vault
5. Do some 360 flips or hit the shuttle
6. Once on ground, do the Pole Vault trick over and over again
7. ???
8. Profit (I've gotten over $32,000 doing this)
Hope that helps.