I'd like to see a gun that shoots projectiles that heals allies. It should heal more at high range, to increase the challenge of using it. I'd say it should heal 3 hp at melee range, to 15 hp at a decent range like the distance you see on an iPhone screen(zoomed in).it should have an slow rate of fire. This would help in missions to come where bosses would be very difficult.

I'd also like to see very difficult missions that require teamwork and coordination to beat.

Here's an example:
Skilliard

Skilliard has been creating an army in an attempt to take down Skyworld, and must be stopped. He has planned an attack, however you became aware of his plans and decided to invade his ship first.

You first battle through waves of enemies coming at you, struggling to stay alive. After you hold off against the enemies, Skilliard himself decides to come at you to finish it himself. he is in some form a powersuit, backed up by a forcefield.
his attacks:
1: He constantly lets out a series of ranged projectiles, which you must dodge. These deal 5 damage each and move slowly.

2: he calls on the ship's cannons to fire on the area. This leaves circles on the ground marking the targeted areas, followed 2 seconds later by a laser to the target areas that deals 20 damage.

3:time bomb: Skilliard places a time bomb on a random player, which explodes 5 seconds later dealing 25 damage to every ally within 8 tiles(4 bush lengths) of the person casted on, excluding the person it was originally casted on. The key to this would be to have this player get away from others, while also avoiding the projectiles being fired.

4:earthquake: Skilliard orders his ship to perform a rough maneuver, causing players to drop their weapons. You will need to walk to go pick up your weapon.

how to beat him:
You will quickly notice that he's invincible-until you find the 3 emerald crystals in the level,powering his forcefield. Once you destroy these 3 crystals, he becomes vulnerable. These crystals respawn after 30 seconds of them all falling.

You'll likely need the heal gun to keep your allies alive, but they still will need to dodge most of Skilliard's attacks to stay alive. It's technically possible to beat him without it, but very hard. This heal gun should be earned in an earlier mission.

Any thoughts? The name and story and all that isn't really an idea I just needed something to prove the concept.  

MEDIC!  

I am fully charged!