Well, that didn’t take long. Not in number of days, anyway. In number of attempts, somewhat more.
The last few levels were somewhat difficult (especially the Cops vs Alien Robots one), but the actual last level was pretty easy, requiring only a couple of tries.
Very enjoyable game though. Much better than Gitaroo Man. I just need to go through it again now, on one of the harder modes. Possibly. Or not.