GBADev forumer SaruCoder put together this video to demonstrate how platformers -- Metal Slug in this case -- can be played on the DS with the system held sideways.
The sound effects are annoying, and the mocked-up game takes a lot of liberties with Metal Slug's mechanics and pacing, but it's interesting to see someone else besides Tecmo take a stab at this book-style approach for an action-heavy title. We're not so sure how much we would enjoy holding the DS with one hand while moving around with the directional pad and tapping the touchscreen directly above it, though.
