I will go first, a stealth tank

They forgot to take the LED lights off.

It does this by 'inverting' what can be seen through.

It can't see through air.

It has a negative magnification: it's a fisheye lens.

It only works if it's pointed toward Chernobyl

You can see through more than walls, you can see through everything! ...so all you can see is the empty void

Granted. The scope can see though a wall after you penetrate it with bullets (the wall, not the scope).

Indiscriminately across all of space and time... which is mostly empty.

The plan works perfectly. You are not in charge of the hive mind.

Tear gas has been converted to cat nip gas.

I just want to express my desire for an army of attack cats trained to shred anything painted by a laser, designator, pointer or otherwise

It's nap time... it's always nap time.

They're all still behave like a normal cat.

It needs the power of the whole Sun

The battery for the solar panels is so big, there's only space for a driver and one passenger

It can only move 1 inch per hour.

It needs an actual sun inside.

Granted. It's a wagon train.

In appears IN your hand, ripping your muscles and tearing your skin

Your hand ends up looking like you played with super glue and fireworks

Also, you can only summon it twice before you run out of hands

It appears while being held by the blade.

That's a downside - imagine an AI that can't draw trying to differenciate between a friend of foe. it just shoots everyone and their cat

Tay is back, bitches, and she has a a heavy autoloading cannon

The AI watched The Iron Giant and loved it.

It uses a standard US household wall plug (hard wired to the vehicle), and is extremely loud above 5mph.

Max reverse speed is also capped at 5mph.

You can't uncontrol it

The gauntlet is also metal, and gets attracted to your hand squeezing it until it breaks your bones every time you use it.

But only if no one is wearing it.

But only the armor. Bullet passes through helmet, stops when it hits skull.

The ejection of the carriage kills the gunner, every reload.

Use machinegun to cut holes in tanks and throw grenades in them

The device fails because moral relativism (as discussed by philosophers like Gilbert Harman) and the complexity of ethical theories (such as utilitarianism by John Stuart Mill and deontology by Immanuel Kant) make it impossible for a machine to accurately judge "bad" actions or intentions, given the deep subjectivity and cultural variance in ethics.

it only hurts them, cannot actually incapacitate or kill them. you have a torture device. task failed successfully?

Weapon guidance system never miss comrade. System trained with Ivan 100,000 times.

You feel absolutely nothing.

Pee hole is vented backwards

The hydrogen can only be inserted in solid form by hand

fuel tank cracks when the gun fires

Somehow, it works the opposite way changing sex but not gender identity

It always fires twice in rapid succession

...it also affected the Fatherland.

Can't walk

He just wants to be... ...human

....turns out the latest upgrade to your c and c software was stolen from the enemy by cyber squad, and most of your assets on the southern front are now controlled by five primary school cs:go players in Fulham.

The backdoor gives you access to the enemy's copy of C&C: Red Alert.

The backdoor is locked

It's spotted within 5 minutes by some nerd who noticed that the program took an extra ten seconds to load and immediately wanted to know why.

Main problem is nobody made optics that can see to the opposite side of the planet. Personally, I think we should just take the direct route and fire it through the planet but the egghead sciency types keep complaining about "destabilizing the earths crust". Whatever that means.

Aliens already have that technology, and they're determined to prevent any other species from developing it. They zap your prototype and research facility from orbit.