MIRNY guide for the braindead:

Grind path from zero: Win 1 easy game. Win 1 Medium Game. Platoon grind 1 Hard game. Unlock Grenadier. Choose: Solo carry easy mode with Grenadier to farm keys. Solo pub medium mode with Double for keys. Fin.
Equip both heals and the instant reload consumables. Press X to speed boost. CTRL + mouse click on the map to indicate where the team should go next. Somebody has to take the lead like a boss or you'll all die. The Shield is one alternative consumable that will protect you from those goddamn painful hedgehogs. That bar above the map fills up as the Immortal gets closer. If it's right on top of the team, you'll want to run away without fighting anything, just go to another beacon.
Play as the Double. You can pick the Hornet only if you are good at active scouting. Pick the Double if you don't know what active scouting is. Hold the fire button down to fire both barrels at once. Blast the bots in the side or rear with both barrels, love tap to finish, turbo ram kill another bot or two even, press 6 for instant reload and derp another bot. With luck you can kill 4 bots in a few seconds, which makes it tough for your team to compete for keys. Save the speed boost for ram kills as much as possible. Run away from hedgehogs, and shoot them if they are moving directly away or towards you, they are usually too fast to shoot moving sideways from you.
The Hornet player needs to keep his team alive by shooting the hedgehogs. Just do damage otherwise.