Fancy Pants is one of the best flash games ever.
Is there some way to download it, so that I can play it offline?
Right click and "Save As" this direct link to download the game: The link
Usually if you download the .swf file, you can activate it offline; though some games prevent it.
How to download the .swf in Firefox: right-click the page, select "view page info", choose the "media" tag, search for the .swf file and save it with the "save as" button.
Once the .swf file is downloaded, you can open it in your favorite browser (click file->open, or just drag it in) and it should work.
Just a tip/alternative method:
Even if you don't use it on a regular basis, Internet Explorer is the best to get files like videos and flash from websites, because it asks for no extra plug-in or add-on. It stores everything in the "Temporary Internet Files" folder. You can just wait for the game to load in it, and then get it on this location on your computer:
Open either Microsoft Internet Explorer or the Windows Control Panel.
In Microsoft Internet Explorer, open the Tools menu and choose the Internet Options... menu. In Control Panel. open the Internet Options list item. In either case, a new window titled "Internet Properties" appears.
In the Temporary Internet Files section of the Internet Properties window, click the "Settings..." button. A new "Settings" window appears.
In the "Settings" window, click the "View Files..." button. After a brief delay, a new Windows Explorer window appears. This window displays all of the Temporary Internet Files stored on the computer and their location on the local hard drive. The window also displays the URL where each temporary file came from.
All youtube video\flash games you've played are stored here for some time. There will also be a lot of other files like images and scripts and stuff...use the search bar to filter and show .swf files only. The title of the file should be something like the title of the game. If you can't find it by title, you can find it by the internet adress which is on a column nearby.
After you find the correct one, copy it to the desktop (or any folder you prefer) and run it. You now have the offline game for playing.
Note: If you ever clean your "temporary internet files", or use pc-boosters like NitroPc or CCleaner, the files might be deleted from the location, and you need to access the file on the net again.