Angel Kids: Ascending Human Breakout.
There are two pieces of hidden text in the game. The first is in the main CPU at 0x0069:
----- All Assemble by Crow in this AN EXA PLANNING Ver 1.10 Res 02.21 -----
The second is in the sub-CPU at 0x0006:
COPYRIGHT VER 2.0 87/05/30 DATA 87/07/14 SID VERS
This astronaut-looking enemy was likely meant for an unimplemented 8th stage. Note that since each stage bank also contains its own enemy and object palettes, and the 8th stage bank doesn't exist, this isn't the correct palette for this enemy.
To see this enemy in action, set address C300 in the main CPU to 08 after entering Stage 1. It'll be just after the first two red balloons.