First, sorry if it offends, but a note to the story/plot... The "chair-escape" was a little cheesy.
Had the same dilemma, myself, in a written story for a Lit' class in the day. I finally decided, the big brawny detective (my story's protagonist) would find a way to rock the chair over and break it through wrestling moves... Just a thought, rather than "the random floor breaks and accidentally frees the guy".
Animation is growing/gaining... And it is possible to exceed your own resources to the file without deteriorating the file. The only trouble is that YOU won't know about it without feedback. It's also part of why sites like this are indispensable to animators, especially those without unlimited resources and computing power.
Seriously, though, if you haven't... check out stickpage.com... You will NOT be disappointed. Terkoiz and others are amazing with this kind of thing, and you can glean a lot of inspiration. I'm actually fairly confident that you have already, but repeat the tours. Trust me, from time to time, you will find new stuff (okay, new to you anyways) that you just hadn't really looked at before.
I know this seems rather rushed (as in my process of review for you) but I like to give someone a few "episodes" or "posts" before I weigh in. It lets me let them see their growth as an artist... AND I'm patient (possibly one of my best/worst attributes)... LOL
I'd still like to see you backstep a little while and develop a storyline. Build a story board, which should look like a flow-chart so you can create the conflict from its original incident (Literary ref : inciting incident) to it's growth to climax and its ultimate conclusion... But... If you're just working out kinks and getting into your animating "swing of things" you grow as YOU need to.
Here's hoping to see further improvement, and growth. Wish you the best of luck... And remember, while this is an artistic growth site under peer review, WE at NG are still just another "Peanut Gallery" and YOU (the artist) need to gather your strength to weather and forge onward!
Art is STILL NOT for the faint of heart... Never was.

Very impressive...especially for pivot animator,smooth speed and good quality makes it quite well made..one problem is how short it is...but alas' i was the same way with pivot where i would make it real smooth..but too short..anyways good job and can't wait to see more! :-)