Yes it is possible to make a mini game in VB.net using GDI+

I've created a very elaborate 8 way scrolling shoot em up game with parallax
scrolling.

I've designed it to actually design multiple types of games, in essence a
game creator.  I've created a tiling engine that can be used to create Super
Mario, Sonic the Headgehog, or even a complex shoot em up games.

You'll need to learn how to do some collision detection too.  That was the
hardest thing for me to do in .net, but I was able to make it work quite well.

It runs really fast as well.  Just remember to do double buffering on the
vertical blanks to get rid of flickering...

good luck dude!