Mass Effect playability/controls question

the second one is bit more action based, and there is a great increase in the game playability, much smoother than the first.

The first one is more of an RPG than a shooter. The movement isn't much different, but the shooting and all that changed a lot in the sequel. They even added reloading in 2 when in the first guns just had to cool down if you shot too much, makes sense since they aren't firing bullets, but plasma or whatever. They blamed it on heat, saying the clip absorbed the heat and you could easily eject it and keep firing. Whatever, I still like not having to worry about ammo.

Are these two worth the money?

ME1: Health requires medkits to heal, shields are large but slow to recover, unlimited ammo but some cooldown time, no gun variety. Plot is story driven with fewer characters.
ME2: Cover based shooter so health/shields are very small but rapidly recover after a few seconds, finite ammo but quick reloads, better gun variety but a distinct lack of upgrades. Plot is character driven with fewer core story missions.
ME3: Origin exclusive. Still a cover based shooter. Much better gun variety. Plot feels more like ME1, but there's no real ending. Tacked on multiplayer required to get the "good" ending.

Personally, I much prefer old-school shooters where I can soak a few hits and rambo my way through a room instead of cover based combat where I have to take turns exchanging volleys and conserving my limited ammo. It made ME2 and ME3 feel slower for me. But they were undeniably better polished in just about every other way.

That said, yes they are worth getting if you don't mind a trilogy ending after 2.9 games. As third-person action games, I don't think motion sickness will be as great an issue as it would be with a first-person game.

All three Mass Effect games have basically the same controls. Differences are small.