This is for scoring 500K in one game and continuing resets your score to zero. Coming into level 4 on easy I usually have about 400k and finish the level up in the level with about 625K. So, about the middle of the 4th level you can get this achievement on easy, they up the points in level 4. There are 2 extra lives along the way you should grab and they are not that hard to get, looks like a big orangish heart. As dumb as this sounds your best bet is to not die. You can collect 4 orbs at the most to float in front of your ship. You can use LB and RB to move them. You can spread them out or move them to the back of your ship which is not that useful most of the time. Then there are 3 different color power ups that change the shot pattern. Blue shoots straight, looks like lasers, if you spread these out. Green bounces all over the place and the orange one is just spread out in a spread pattern going straight and diagonally up and down. Once you get hit you spit out all of your upgrades and have a chance to catch some or all so catch them. Sometimes if you get hit and don’t pick up any or very few power ups the game is just too hard.