A lot of the functions are mentioned via dialogue and aren't apparent in the combat system, but here's a rundown of suit features I wrote for an old app:

"

sealable compartments: in case of a rupture, the breach can be isolated to prevent contaminants from spreading

kinetic barrier generators: (Kinetic barriers at the Mass Effect Wiki) the suit has small, built-in mass effect emitters that create kinetic barriers (colloquially "shields") to protect the wearer from gunfire and other rapid-velocity physical impacts. They provide no protection from damage such as radiation, toxins or sonic weaponry. They can be depleted and must then be let recharge before they are of further use.

space suit functionality: the suit is space-worthy, allowing the wearer to function in a vacuum or hazardous/unbreathable atmosphere. Its oxygen reserves are, presumably, refillable but limited.

atmospheric filters: the suit's filters can keep away smells, harmful gases, and most importantly airborne micro-organisms. Tali mentions programmable olfactory receptors and anti-nausea filters.

audio filters: the sound receptors of the suit are similarly adjustable

medical functions: the suit contains built-in medical scanners, immunological boosters and automated medi-gel injectors to immediately attend to injury or the presence of harmful micro-organisms"

Mostly I'm wondering about the shield system, since it lets the suit double as a kind of armour, and those don't fly in every game. However, having poked around reading some accepted apps, maybe this isn't a problem?

And the medical functions are kind of high-tech, I guess. :)