Kill The Monsters In That Area Then Move Away Till The Area That Had Monsters Is There No More.

Then Go Back To That Area & Monsters Will Be There, Kill Them Again & Again While Gaining More Points To Your Score.

When You Die The Deleon Will Pick You Up, Afterwards For A Short Time You'll Become Invincible.

When A Delorean Picks You Up Or When Is Summon & Manages To Hit A Near By Monster It’ll Drop A Key For The Doors Which Makes Getting A Key A Lot Easier Then Going Through Entire Level For It.

Or At Most When You JUMB Out Of The Delorean Being Temporary Invincible To Kill The Monster & Get A Key.