Inventor isn't what you should use to make game models as it's for creating solid models moreso than the kind of regular surface models that you use when making art assets for games.
I remember that you can get a .obj exporter for a inventor, but I don't recommend doing that because the exporter will preserve way more detail than you want or need for game art causing your models to be way too expensive.
Proper modeling for games is way different than the kind of solid modeling for design, many of the skills you learned for your design models will not carry over to game models. For game models you want to try to express the most detail you can with the fewest polygons or expensive shaders, opposed to design models where you want to recreate the shape as accurately as possible and the number of points/curves/whatever are (somewhat) irrelevant as long as the end result is accurate.
So If you're really interested in creating models for source I recommend you pick up trial version of either Maya, Max, or Softimage as they're more suited for the task (despite what anybody says, you can't go wrong with any of them).
About the model, it's nice, but the proportions are a little off
Your version of FLUDD looks like one that a normal person could use, whereas the one in Sunshine had thicker/stubbier handles for Mario.
and omnicoder, why do you say the reflections won't look like that in source? Cubemaps in Source are also HDR images, so it should look the exact same given the same environment map.