This is just a few adjustments that'd help UFO mastery fit a lil more neatly in the game, and fewer complete immunities to most abilities.
*Dropping the UFO into the dead zone below the main piece of land destroys the UFO, and kills everyone inside... Don't fall!
*A UFO can remain in the air for 1 minute at a time, before having to land, however... Landing lets you recharge incredibly fast. You can fully recharge after 5 seconds being landed.
*Mini UFO's can be destroyed with 2 punches.
And now some fun lil bonuses to make up for UFO losing most of it's greatest perk, near invulnerability.
*Mini Ufo's have their own unique ability to fire a short ranged laser that does 2 damage. It's weak, but it's meant to be used in conjunction with several other mini Ufo's to rain fast fell. 1 second cooldown.