Don't Die Mr Robot - Arcade mode world record - 1658213

Like most of the high scores in the game, this is set with the Dunjun Dude optional character (look under "Special Guests" in the in-game shop, costs 2000 coins). He's easily the best in the game; that key that follows him kills enemies on contact, and when you get fruit, you shoot friggin' laser beams for a few seconds. The basic strategy I use is to let the fruit build up as much as possible while I stay in a corner, defending myself with the key. When my strong shield is gone, I wait until there are some enemies on the screen and then grab a piece of fruit, triggering a massive combo.