☻ - enemy
☺ - user

▼ - enemy shot
▲ - user shot

█ - wall
▓ - damaged wall
▒ - quite damaged wall
▒ - really damaged wall
⚹ - explosion

╔ - dr border / boomerang
╚ - ul border / boomerang
╗ - dl border / boomerang
╝ - lu border / boomerang
║ - du border
═ - lr border