So in other words like the "Meowth's Party" demo for Gamecube, where the code in it was never included in any other game. Not even in the eventual Pokemon spinoffs on Gamecube (Collessium, XD, Box, Channel).

The theory that they became other games also holds up. Remember that code from the "100 Marios" demo on Gamecube eventually went into Pikmin and Super Mario Galaxy. Alternatively they could be just placeholders for other titles - Super Mario 128 was a placeholder term for any potential sequel to Super Mario 64 over the years.

As a final thought, I doubt Federation Force has been cancelled. Nintendo never listen to their fans, so they've no reason to cancel it.

They're not going to get rid of Federation Force just because some unsupervised children with an internet connection needed to throw a temper tantrum about Zelda's delay. They might do some extra polishing to shove a figurative pacifier in the trolls' mouths, a la Starfox, but cancellation isn't a realistic possibility.

Yessss.

Those were testing demo's, most likely for Star Fox

So ... these games weren't meant to be games even though they were called games, had demo booths, and were given release windows?

Story checks out.

People have been overreacting to Federation Force. No, it's not really a Metroid game, more a game set in the Metroid universe. I have no problem with expanding the univers. If anything it was Halo 3ds with a rocket-league like minigame. Doesn't mean it will be terrible. Seems like an ok spin-off game to me.

The Project Guard and Robot probably did, but may come back in some minigame

#FE won't but I'm not sure about the other 2

The project games are the only ones that have a chance of getting cancelled, the other two are safe (even with the amount of backlash nintendo got for Federation Force)

"I have a feeling that Nintendo cancelled Metroid: Federation Force"

I will laugh heartily if this happens.

Nintendo will not cancel Federation Force. Never. If they did, "fans" (notice the quotation marks) would think that they have major power over Nintendo's decisions, and Nintendo would never allow that to happen.

Nintendo are doing too many mix & match, and mash up, and spin-offs.

Time to release some games that are actual sequels to things people want, instead of constantly trying to reinvent the wheel.