$999 is indeed possible. :) The dark room with the piggy bank didn't open the first time I played despite making the noise of a moving wall. Something must have glitched. I collected it easily the second play through. I noticed the change to the purple killer-disks on the screen before the boss. Having one rotate instead of all up and down makes this a bit easier, though still a challenge. I also love the filter on the graphics which makes it look like an old CRT monitor! Wow, very retro! But, consider making it an option like invincibility to turn on or off. Cheers! 