The first play-through on Insanity was not entirely easy, but a walk in the park compared to some of the other classes. A strong character style with well rounded teammates can make even the most difficult settings like a picnic next to the sea.
This Shepard may have been more intended for a "Tank" character to stand on the front lines and soak damage and not the ideal class for a first (or second or third) play through on Insanity mode.
However, a properly played Sentinel not only opens up a useful way to beat the most difficult setting of Mass Effect 2, it also allows the player attempting Insanity mode not only bearable, but maybe even a little. . . "fun".
The most important part of this play through will be to use your powers as effectively as possible.
-Tech Armor is a lifesaver as an offensive and defensive ability. Tech Shield provides an extra shield boost making it an amazing damage soak, allowing a player to take more shots while putting down as many enemies as possible, as fast as possible. On the offensive side of that coin your tech armor deals damage and knocks back close enemies when destroyed.
-Warp shuts down an enemies health regeneration permanently, and does a number on both armor and barriers.
-Throw knocks enemies to the ground and pushes them back, buying you and your teammates more time on advancing opponents.
-Overload deals heavy damage to the enemy shields allowing you to deal damage to an enemies health or armor while saving valuable ammo.
-Cryo Blast is the final ability in the Sentinel's skill set and freezes an enemy dead in its tracks, frozen enemies take extra damage when shot.
Weaponry is also important for obvious reasons. Getting your hands on a Locust SMG from the Katsumi downloadable content and taking the assault rifle training option when it presents itself will put yourself leaps and bounds into the right direction.
The other two recommended weapons are the Phalanx Heavy Pistol and the Arc Projector which are also DLC weapon pack weapons.
-The Locust provides a large amount of damage to those pesky shields and enemy health.
-Rifles are always a great choice, especially when you choose the Mattock. Rifles are generally good against any type of defense or health an enemy has, and makes a great weapon when fighting mix groups of them or simple to take out opposing squads quickly.
-The Phalanx is a great choice for armor reduction and with a laser sight makes head shots even from medium-long range a breeze.
-Finally the Heavy weapon of choice, the Arc projector. This weapon does a number on entire groups of enemy shields, the fact that it bounces from enemy to enemy can make easy work of enemies in cover, close quarter fights, and enemies that makes assaults in packs.
If you are playing Mass Effect 2 and have access to bonus powers, Warp Ammo makes all weapons deal heavy damage to Barrier, Armor, and Health. The final tier of this effect allows you to use it for either your entire team or yourself with a large bonus to weapon damage on top of the ammo ability.
Shepard's teammates are important to your success. Both Garrus and Miranda are highly useful characters both with Warp and overload abilities, shredding enemies layers of protection and getting to the health of opposing forces moments into the start of a battle.
Garrus has a Concussive Shot attack that knocks down enemies just as Throw would, and can instantly kill Husks. With loyalty comes perks. Miranda has slam which is great for enemies at their health bar, and can be devastating when combined with an effect like Warp. Garrus on the other hand uses Armor piercing rounds.
From here the game almost plays itself. Follow this basic outline, and except for the times when a little improvising will be necessary, you will have no problem crushing your opposition.
*Prepare your Weapons
-When combat starts, take cover and open your weapon wheel. Take a look at your characters and decide what weapons you are your teammates are going to be most effective with.
*Pick your Position
-Order your teammates into strategic positions to minimize your chances of being flanked or rushed, and allow you the upper hand, or potentially an opportunity to flank the enemy while their focus is spent on your allies.
*Take Their Lives
-Pick your first target, open your team's power wheel and unleash all the fury you can muster. After your first assault of powers just continue to work your weapon and powers strengths and your enemies weaknesses for quick, clean, and relatively stress free game play.