I think I found my 4 games: Mighty Flip Champs, Shantae, Dark Void Zero, and Soul of Darkness. Should be 3000 DSiWare points. I still have the 1000 from the DSi launch.
I own all of those.
Mighty Flip Champs is a fun puzzle game, but it gets hard fast. Don't expect to finish it.

Dark Void Zero is fun, but it's only about an hour long and there's not much reason to replay it.
Soul of Darkness is a pretty fun, if somewhat janky, Castlevania clone. Lots of fun, but nothing you haven't seen before (especially if you're played Order of Eclisia, which it most strongly resembles).
Your list is missing Pictobits. It's the best Art Style game on the DSi (and probably the best one period). If you like puzzle games you should strongly consider it. Also, the music is sublime.