The aliens don't have Gold Fever just because it's shiny.
Dolarhyde is bewildered by the aliens wanting gold; "What are they gonna buy?" Answer: gold is an essential component of their gravity tech(and any weapon that Blows Enemies Across The Room violates the conservation of momentum, so their weapons are also gravitic). When they abduct Lonergan's girl, the gold coins on the table melt and fly into the air. Their method of mining for gold involves gizmos that do just that, but why would they be using said gizmos on a little house on the prairie? Any gold within range of the gravity effect will melt and float, similar to magnets magnetizing ferrous materials in contact with them.- Just out of curiosity, gold is essential to the operation of electronic devices, correct?
- Some devices. Gold does have properties that make it intrinsically useful. It doesn't corrode, it's an excellent conductor, and it makes good radiation shielding.
Ella is a Ascended Ancient
She takes human form to save humanity from the aliens, which are probably at least partially their fault. Either they really did destroy the Ancients (unlikely) or she's lying. She may actually still be Ascended, judging by her regeneration. Nobody ever believes the cowboys' story, and the existence of aliens stays secret for over a hundred years. Also Reapers.- If she was an ascended ancient, she could have blown up the ship without descending extremely easily. The penalty for her would have been exactly the same.
The aliens will invade again ~100 years later
And go up against nukes and missiles.- Their invasion is captured on screen in Battle: Los Angeles. Sgt. Nantz is a descendant of either Dolarhyde of Lonergan.
- Except those aliens don't look anything like these aliens. And the BLA aliens were after water, not gold.
Ella doesn't die at the end
She took on a different more transportable form and left Earth to save other planets. There's presumably still more of them invading other planets, as Ella says the ones on Earth will come back with reinforcements later.- Given she was apparently revived by fire burning her corpse, it seems quite plausible for her to survive an explosion in a similar fashion.
Ella is a Time Lord
Come on! She regenerated, for cripes sake!- Nope. If she is following the Dr. Who rules for regeneration she would have died permanently when they burned her body, even if she normally could regenerate. Interrupting the regeneration process of a Time Lord, such as burning their body, kills them.
- She might have done something similar to what the Tenth Doctor did to avoid changing body. One of her lines also seems to imply that particular bodies can get worn out, suggesting that she would have to switch to a new body.
Ella is an Energy Being
She doesn't shapeshift, she creates a physical body to inhabit, although it usually takes a while to grow one, so she can't just reappear instantly. When she revived the first time, the fire provided enough energy for her to heal her own corpse. When her body was destroyed in the end, she just returned to her original form and left. The mining town is actually Roswell, New Mexico.
Aliens. Need I say more? New Mexico is out west, and it's deser-ty enough...
- Except this story had actual aliens, where as even most of the original proponents of the Roswell Incident involving an alien craft haven't believed that about Roswell in about 15 years.
The Aliens stole the ship and acompanying tech
They're basically space cockroaches with a modicum of intelligence; enough to fly the ship and fighters, and use some of the tech, but they don't really know how it works or how to modify or repair it. This is why they had to mine on a habitable planet: they can't build or operate an asteroid mining facility, and they're too stupid to think of it anyway.- That explains why their aircraft engines are so inefficient at burning fuel, though this troper believed it was because they were using petroleum fuels (mined on this planet along with the gold) in an engine not originally designed for it.
The Aliens are ancestors of the Psychlos
They share the same lust for gold and crippling stupidity that allows humans to defeat them. Between the time of this movie and the time of Battlefield Earth, they evolved from reptilian creatures to those idiots. The kiss Ella plants on Jake was magical/telepathic like the one Superman used on Lois Lane.
She kisses him, the weapon falls off. Obvious. The events of this film are an alternate timeline - reverse engineering the remains of the ship sets off the Steampunk revolution.
Ella is Quorra
The whole movie takes place in a mostly isolated part of The Grid, where the graphics are styled like Westworld, rather than in shiny-black-and-neon. Quorra was sent to save the townsfolk, bandits and indians (who are all programs) from the aliens (a virus whose weapons are hacks) who are stealing the molten gold (data streams). Ella|Quorra doesn't die and resurrect; she is de-rezzed and rebooted. The aliens are mercenaries.
One biologist to examine the natives on the target planet and a bunch of not particularily bright brutes who are supposed to fly, push buttons and dispose of possible... irregulations. The ones who actually know how all their tech works aren't present (except for one or two for maintenance) and the heads of the whole project might even be of a completely different species. The aliens work for the Psychlos
The Psychlos force the aliens to mine gold for them, lending some of their technology and sending them off to unpleasant planets such as Earth (which has air that is acceptable to the aliens but toxic to the Psychlos) to look for gold. When the scout ship is defeated, the aliens say nothing to their Psychlo masters for fear of retribution, and quietly erase Earth from Psychlo records. The Psychlos are none the wiser until they come across Pioneer 10. At this point, they decide to cut the middle man and invade the planet themselves.
The aliens' secondary arms and internal cavity are used for tending to and growing their babies
Similar to marsupials, the aliens go through a vulnerable child phase where they will walk around outside the parent when it's safe but return to their "womb" for nursing and protection. When the species became advanced enough to create and use delicate tools, the secondary arms became used for that purpose.