If you're new to playing these games, or how to use the game, here's a short guide:

First, you need to get a 'NES Emulator'
I would recommend the latest version of VirtuaNES or Fceux.
www.emulatorzone.com

Then download a Mega Man 3 (USA verison) ROM somewhere, or dump it yourself from a cartridge.(Don't ask for links, distribution of ROMs is forbidden)

Now the .ips file is not what you want to run.It's simply the list of alterations between two files, the original game, and the hack.
Get the patch applying program 'Lunar IPS'
http://www.romhacking.net/utils/%5B240%5Dlips102.zip

Then apply the "Mega Man - The Hedgehog Trap.ips" to the Mega Man 3 ROM file.This will overwrite all the data in it and exchange everything to the new.

Run the game with the emulator, and there you go!
Have Fun!
