2,133,500
I completed 3 loops, and had my first death on loop 4 level 6. I had something like 20 extra lives at that point, but no matter how hard I tried, I just couldn't finish off that level. A few times I managed to get back to laser and that helped grab a few more points.
One time I actually got laser and a shield back, and made it to the boss. I had no options, so I just had to hope my shield held up. My shield finally dropped, but then the boss died!........ but one of his final projectiles took me out, as he sat there with parts of his body already dissolved.