gamedev
I've changed the ocean tiles for the alien planet tileset from red to yellowish green (trying to make it look like some kind of acid) because the bullets and the player's crosshair blended in with the red oceans. I originally wanted to make the oceans yellow (color of sulfuric acid which could be an alternative to water for alien life forms) but the yellow oceans would've looked too similar to the sand tiles.
gamedev
@beardalaxy According to Sakurai in his video, a freeze frame is necessary in shmups because sometimes you die so quickly, you don't even know how you die. So it's best to have a freeze frame to show what hit you.
I could also replace the tile background with a solid color for an added effect.