 "Defender 2000" builds upon the gameplay from the original "Defender" by introducing more power-ups, bonus levels, more and sophisticated enemy types and level designs varying in thematic, among other new additions.The game features a total of 100 levels, with new color variations for the stages after level 50.Progress is automatically saved after completing five levels via the cartridge's internal EEPROM, which also keeps tracks of the high-scores and other settings made by the player across the three game modes available at the start of the game.