How to Cheat:
Enter the following codes at the 'Cheats' menu:
levels - Unlock all levels.
primus - Unlock Rath alien form.
classic - Unlock Fourarms alien form.
cash - Get 1,000,000 DNA cash.
hard - Harder mode [AI does 2x damage, player does 1/2 damage].
energy - Regenerate energy.
health - Regenerate life.
upgrade - Upgrade every alien form to max.