No valley too deep, no mountain too high....

Some updates to Op Attack. 

• The enemies have been replaced with pre-rendered voxel sprites.  These were made with MagicaVoxel and then rendered using SpriteStack; the latter software appears to be moribund and no longer receiving updates.  Spritestack only supports lighting from the upper-right fore, which is  a shame because directly-overhead or back-lit would be useful. It also has some fiddly pixel rendering, so these sprites were made at double resolution, then rescaled, and then post-processed to two-colors. 
• The animation of the backgrounds have been tweaked. All have been keyed to the display frame-rate (instead of an arbitrary fps). Earlier builds attempted to create 'false colors' by flashing the image rapidly. While in theory it would be possible to key the animation precisely to the frame-rate to cause the flicker, in practice a lot would depend on the display of your hardware.   The strobing backgrounds have been removed. So were the static ones, too.
• The splash screen has been updated to include a credits roll. The splash screen is on screen for quite a while because when the game first starts, all images are pre-cached. Some of these backgrounds are in very large textures (8192x8192), so it's better to pre-load them.
        I've been considering an HTML5 release to run in a browser, but I'm worried these un-optimized textures won't render. I could spend a fair amount of work fixing the backgrounds to be tiles, which would require less processing power, but there's a lot of issues there (such as changing the frames to be multiples of 2.)

They say to make the art you want to see in this world, and I still enjoy this little game. I hope it might bring you a little happiness, too.