Video game idea: Fall or Die Trying

Concept

Guide a small ship, dropped from the mothership in orbit, hundreds of miles down a massive fissure to detonate a cataclysm device at the planet’s core. The faster you fall the faster your shields recharge, braking is accomplished by rubbing against the edges of the fissure but will cost you shield power. As you approach the core the fissure narrows and your shields strain against the immense temperatures.

Knowns

• Falling gives you score.
• Accelerating beyond the pull of gravity increases score gain.

Unknowns

• Pickups / powerups.
• Time limits.
• Ability to detonate the cataclysm device at any point during the fall.
• Ship upgrades.
• One attempt per planet: Proceed to later tiers by performing satisfactory amounts of planetary destruction in your current tier.
• Moral decisions: Option to decline missions that involve populated planets.

Did I miss something?