Construct 2 is a powerful ground breaking HTML5 game creator designed specifically for 2D games. It allows anyone to build games. We at Cidade Art Productions use this intuitive and easy program to create our games. Try it HERE.
A great resource for free sounds that you can use in your own video game. All you need to do is register first. Check it out HERE.
SaviHOST and VSThost are both great for making music with different VST files (instruments). They also support MIDI keyboards for that authentic keyboard play. Try them HERE.
Audacity® is a free, open source, cross-platform software for recording and editing sounds. Its great for putting your music tracks together and editing sound files. Try it HERE.
DefleMask is a free Cross-Platform tracker for producing music for many soundchips and old school systems. Download it HERE. SNES GSS (Game Sound System) The sole purpose of this software is to make music and sound effects for SNES homebrew games. Download it HERE.
Also check out these simple web based sound machines Bfxr HERE and AS3SXFR HERE.