Have you ever played Boulder Dash and asked yourself "I wish I could blow up everything in these mines with lasers and explosives"? Crystal Mines II has you covered.
Level Select#
Enter password KIMI, then confirm by holding Option 1 + Option 2 and pressing B. At the pre-stage prompt, press A and B to change the level, and then any direction to start.
(Source: GameFAQs (Crazyreyn))