You need to use the software Adobe Flash.
Unfortunately this software is not free, and is priced ridiculously, but you can get a 30 or so day trial, with no restrictions.
To download, go to the Adobe website and click the Flash button (NOT flash player), and then download it from there. There are also alot of tutorials online, just Google Adobe Flash tutorials.
The only way i know of is to get a program that uses flash and action script such as adobe flash CS3
You can try to make flash games or text games with Java, C++ or any other programming language, but that takes a long time and you have to be experienced in programming.
You can create flash animations. You can also make games. However, the program is $600.00.
You'll need some web designing skills and Adobe Flash or get some website flash templates.
By hacking
You can't create your own moves in Pokemon video games, unless if you hack.
Maybe!!
poptropica
Adobe Flash standalone is a software application that you install on your computer in order to create and edit Flash/Shockwave files. It's standalone and can work on its own. The Flash PLAYER, however, is a browser plugin that plays the published end results of the standalone Flash software. The main difference is that Adobe Flash standalone can create and edit, while the Flash Player can only view/playback.
You can download flash games from adobe flash download or Java Download
I think u can actually create a new sport, because in my school we had to create our own sports.. u can if u want...
Macromedia Flash is a Multimedia program created by Macromedia. You can create Animations, Edit Videos, Create Flash games for computer and cell phones and save them as multiple forms like .exe or .swf (shockwave Flash) which plays things made in flash. You can Draw pictures and save them as multiple picture formats, and even Create Websites using this Wonderful Program. Personally, it's my favorite.