These overlays (sometimes known as bezels) display art on top of the game you're playing. To use them, you need a PC or Raspberry Pi (or other compatible system) running some version of MAME and the associated game software, as well as a widescreen (16x9) monitor mounted vertically. To display the overlay while playing a game, download the artwork file for that game overlay (it must have the same filename as the game), place it in the Artwork folder within your MAME directory and launch the game. (For instance, the software for the game Magic Sword is called msword.zip, so it requires a file in the Artwork directory also called msword.zip.)
All overlays are 4K resolution (2160 x 3840), and listed dimensions are for the game screen, relative to a 4K vertical monitor. The actual game screen size will depend on the resolution of your monitor.
Most of the overlays include multiple presets that let you choose the size of the game screen, access a "dark" version designed to look more like a dark arcade, and sometimes other options. To choose a preset, press Tab while running the game to bring up the MAME menu, select Video Options, and select a preset from the list.
Some overlays include Curved presets designed with a curved screen port, to better simulate the look of a CRT monitor. These presets work best if you are using a geometry shader that adds a curved look to the game screen. For an optimal experience, you may need to adjust your shaders to match the curvature of the screen shape in the overlay. If you are not using a geometry shader, you are using a shader that adds a curved bezel, or if you prefer a rectangular screen port, choose a Straight preset where applicable.
Following in the boot tracks of the successful Ikari Warriors, SNK released Guerrilla War to further capitalize on its rotary joystick-powered run-and-gun formula. Unlike the fanciful Rambo-style storyline of the Ikari series, Guerrilla War's story is actually a gamified take on the Cuban Revolution, with its two gun-toting heroes being none other than Ché Guevara and Fidel Castro fighting the Batista regime. Don't expect a history lesson, as the concept and gameplay are similar to the Ikari series, including its rotary joystick aiming controls, but the graphics are improved and overall the game has a level of polish that the original didn't always achieve. As with the Ikari games, you will need a method of emulating the rotary aiming, but a version is available that combines movement and aiming in one joystick.
"These two men were born to fight!" proclaims the title screen of Ikari III: The Rescue, and it's hard to argue with that premise as we follow Paul and Vince once again unto the breach. Sent to rescue "the Presidential candidate's child" from "an enemy terrorist party," Ikari III has the Rambo-like heroes fighting hand-to-hand through much of the game, combining Bad Dudes-like melee combat with the series' run-and-gun formula. It's clear a few years have passed, as the graphics, enemies and gameplay are notably more advanced than the series' earlier games, but it still features the team-up action and jungle setting the series is known for. Ikari III still uses a rotary joystick, but a version is available that combines movement and aiming, making it much easier to control.
One of the most iconic run-and-gun games of the 80s, Ikari Warriors sends commandos Paul and Vince into enemy territory to battle hordes of enemies with bullets, grenades and tanks. Inspired by the Rambo movies and taking its Ikari ("fury" in Japanese) from the Japanese title of Rambo: First Blood Part II, the game's key distinction was the use of a rotary joystick that allowed players to move and aim independently. Emulating the game's proper controls on MAME is a well-known challenge – though it is ideally controlled with a dedicated rotary joystick, you can also use a spinner combined with a two-button flight stick, or map buttons to the left and right rotation of the character (a modified version that combines movement and aiming direction is also available). Whatever your setup, Ikari Warriors is worth another rampage through the jungle.
Prehistoric Isle (presented as Prehistoric Isle in 1930 on its title screen) sends intrepid pilots on a mission to investigate the disappearance of ships in the Bahamas, only to find Greenhell Isle, populated with dinosaurs and other creatures long believed to be extinct. Naturally, "conduct an investigation" translates to "annihilate the entire island," and the pilots proceed to exterminate everything they come into contact with, which includes an impressive array of creatures across multiple stages. Prehistoric Isle mixes up the standard shoot-em-up formula with stages that scroll in different directions, while your plane always faces to the right, and features an R-Type-like satellite that can be repositioned.
Victory Road is the first sequel to Ikari Warriors, and features the same rotary joystick run-and-gun gameplay as its predecessor. Picking up at the end of the first game's story, Victory Road finds victorious heroes Paul and Vince suddenly thrown thousands of years into the future by a mysterious storm, where an alien named Zang Zip has taken over. Unlike the first game's relatively straightforward premise and style, Victory Road features a somewhat oddball sci-fi aesthetic, with hordes of tiny grunts, jumping spider-like aliens, flying insectoid enemies and more. The game also includes quirky sample-based sound effects, starting with a hilariously weird sampled taunt from the villain that sounds more like a pro wrestler than an alien overlord. Like Ikari Warriors, the game can be a challenge to emulate properly, requiring some method of rotating your aiming direction.