I'll look into adding a 7th digit for the arcade port. There are plenty of point pressing opportunities in the game (with hammers on the elevator level, the re-cycling of barrels in the spring+barrels level, hammers on the same platforms as the fireball spawning oil cans in the new cement level...) so I imagine it is foreseeable that eventually there may be a million point game.
It has the same L22 killscreen, the levels up till then are completable in the allotted time, the number of stages per level has the same "2,3,4,5,6,6..." pattern (the stages themselves vary - 3 types of barrel stages, 2 cement stages, 2 elevator stages, 3 types of rivet stages)