That Gintoki not only let the demon in, but gave her the cat's claw (which was too big and looked like a dog's leg)was too much. You knew he was going to get screwed by the demon. Duh
He didn't give her the arm. She tricked him into letting her in, and by the time he noticed she was missing an arm, she had all ready got it back.
He ran around, slashing the air with his sword and yelling, then fell down dead. Stupid.
How was it stupid? Did you just watch things happen without putting any thought into why they happened?
He was out to kill the demon, and was clearly becoming so delirious he would swat at anything that moved, like the mist. He was clearly physically breaking down throughout those last few moments, so him falling dead isn't a surprise. and yelling? Umm, yeah, he was calling out to his mother. That doesn't seem out of the ordinary.
(The other samurai had their throats chewed out by a ghost.)
Those other samurai were also lured in by seduction, making that convenient. She wasn't going to be able to do that with him by this point, so it makes sense she would do something different.
Also would not have been nearly as good of an ending.
This is not a Japanese "fairy tale," but a movie, with a modern screenplay.
It can be both, you know.
but the story is thin
No it isn't. The plot may be simple, but there's a ton of emotional depth.
with a goofy ending
It really isn't. It's bleak, somber, tragic, and poetic."It's just you and me now, sport"
blue guy is partially right. from a modern viewer's perspective, the ending was a bit weak. it was kind of silly (to many modern viewers) that the samurai's letting the mom-ghost in and his subsequent actions. however, if you look at it as a fairy tale (even western ones), it's about inline with the simplicity of what he did. of course the emotions that he was feeling is much more complex than that.