Nintendo to reward purchasers of new handheld with downloadable game currency; Wii store welcomes coin-op classics Gaplus, Mappy, Star Force, and Tower of Druaga.

SAN FRANCISCO–Nintendo continued to flesh out its line of downloadable-game offerings with a handful of initiatives revealed today during company president Satoru Iwata’s keynote address.

Mappy’s a loose cannon, but he gets results.

To mark the April 5 launch of the Nintendo DSi and its DSiWare downloadable-game library, Iwata announced a promotion to give early adopters a free taste. Consumers who visit the DSi Shop online storefront for the first time will automatically receive 1,000 Nintendo points (formerly known as Wii points) to spend on downloadable games for the handheld.

Nintendo also announced today the four main price points for DSiWare games: Free, 200 points ($2), 500 points ($5), and 800-plus ($8 and up) points. As with Wii points, Nintendo points can be purchased through the system with a credit card, or from “select” retailers in the form of Nintendo points cards.

Downloadable gaming on the DSi’s console counterpart is also getting a little love from Nintendo. Iwata mentioned in his keynote that the Wii Virtual Console retro-game store is now offering third-party arcade games. Eschewing the tradition of Monday updates, Nintendo today added a quartet of arcade games to the Virtual Console. Tecmo’s vertically scrolling shooter Star Force as well as Namco’s Mappy and Tower of Druaga are selling for 500 Nintendo points each ($5), whereas the Galaga follow-up Gaplus commands a 600-point price ($6) tag.

For more from the show, check out GameSpot’s complete coverage of the 2009 Game Developers Conference.