And we are closed!
... Ehm, guys, are you... are you alright? You didn't have anything dropped on your head or something? Because if these are your definitions of a Happy Ending, I am a bit afraid.

Let's go through them one by one:
Baron: I think I wasn't quite as confused as JudasFm and think this story could work as a short story. But in general, the scenes feel rather unconnected. We don't get a lot of background information but it makes sense that a rebel group wants to steal money. Sure, I can see that. It also makes sense that they seduce the director of the bank to get some information. The problem is that it doesn't have any consequence. You could leave the venus trap out and jump from the meeting to the (failed) robbery, you could leave out the meeting and just have the last part and the reader wouldn't lose much information.
All in all, it feels a lot like you were going too much for humour. The scenes try to be funny with the classic two people in one coat or through pure grossness but the inner structure of the story suffers as a result.
As for the ending - I was confused. I'm not even sure if they escaped. And if they did, do I want it? The characters did not endear themselves to me at all. That isn't absolutely necessary for an Ending to be defined as happy, but it certainly makes it easier. Also, I think to some degree a story sets its own goal as to what it would need to make it happy. And as the meeting in the beginning sets the bar as "For the Cause" (as in, their revolution) the win the characters do get, no matter if it feels happy in and off itself, just feels too small.
Mandle:In general, I really enjoyed this story. I like how the narrator, having lost his pet, isn't ready to get a new cat but finds some happiness in watching the stray. The kitten finds a family, even though it doesn't look all that good for it in the beginning. Also, the descriptions of the cats are lovely.
But (there's always a but, isn't there) the ending is hardly happy, is it? "If you want a happy ending, that depends, of course, on where you stop your story." According to google, that's a quote by Orson Welles and I think it fits very well on your story. Had you ended it with "On the way back home from a shopping trip I saw two of the grown-up cats of Chibi's litter crossing the road and Panda was behind them, in tow, glancing around nervously and I could imagine that he was just like a young kid out on a lark with older brothers and saying stuff like "Hey... guys... are you sure we should be..." but tagging along nonetheless." and maybe a sentence or two to round it up, that would be a happy ending. But having Panda die? Yeah, I can't see this as happy.
Without the condition of this FWC that the story is supposed to end happy, I think it's a great ending. It's emotional, it has a melanchloc vibe that works well. But that's just it, it's a sad ending.
JudasFm:I was so sure you were going for a fairy tale structure there with the three days of the ceremony. You surprised me there.
The stroy has a lot of small details about the culture of the merfolk, which I quite like. I think it's a bit strange that the princess would find her way into the slave pits and would have liked an explanetion for it, or better yet, a real reason why the princess and the slaves interact with each other. Maybe they are the servants who are ordered to dress her (assuming the merfolk wear clothes), just something that makes it logical for them to meet.
Your ending was the only one that feels at least like it could be happy. The slaves are freed, the wedding allows them to escape... Unlike Baron's story, your characters' proclaimed goal also isn't to overthrow the government, just to get away, so they do manage to achieve what they set out to achive. At the same time, this doesn't feel like an ending, it feels like the beginning of a story. Dirnec and Meruna still have to get away, they still need to build a new life - difficult, considering they seemed to have spend a long time as prisoners and at least Dirnec was too young to be useful when he was caught. Also, they probably started a war, leading to more people ending up as prisoners. Still, this story comes closest to a real happy ending.
Alright, let's add my votes to the mix:
Best Character: Baron
Best Plot: JudasFm
Best Atmosphere: Mandle
Best Writing: Mandle
Best Ending: JudasFm
And that leaves us with the following results:
JudasFm wins with 10 points.
Mandle reaches a second place with 8 points.
Baron comes to a close third with 7 points.
JudasFm, your turn!