Recently the Xbox 360 released Metal Slug 3 on Live Arcade, charging 800 points (10 bucks). If you’ve already picked it up, love it and want more, or have held off picking it up because of its high price point, then this is something that might interest you.
For 40 dollars (roughly 3600 MS points after taxes) you can get a collection featuring 7 Metal Slug games including Metal Slug 3. This collection, available for the PS2, PSP and Wii, is the perfect alternative/addition to Microsoft’s offering.
If the Wii version interests you, keep in mind that you’ll need to have a Gamecube controller handy. The game, oddly enough, doesn’t support the classic controller, and using the included wiimote configuration is guaranteed to drive you insane.
If PSP is your choice, then keep in mind you’ll be facing a couple mind-numbingly long load times (sometimes a full minute). The PS2 version has some load times as well, but not near as long (6-8 seconds). Still, if you’re willing to sacrifice online multiplayer and achievements, want to use a functional d-pad, and want a hard copy of the game which will never disappear when/if your 360 breaks/breaks again, then this is a route you might want to take. For the price of 4 Metal Slug games, you can get all 7.