Defeat the boss in the synthesizer.
Upgrade all synthesizer modules to maximum.
Collect all artefacts.
Defeat the boss in the cash register.
Defeat the boss in the leaking fridge.
Defeat the boss in the antique radio.
Defeat the boss in the vacuum cleaner.
Defeat the boss in the retro computer.
Defeat the boss in the old car.
Defeat the boss in the pinball machine.
Defeat the final boss.
