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.
Batsugun represented both an end and a new beginning for the shoot-em-up genre – it was the last game produced by genre innovator Toaplan, but it is considered to be the beginning of the "bullet hell" or manic style of shoot-em-ups, filling screens with mazes of deadly projectiles. Like a number of games that followed it, Batsugun features a cast of characters that each have unique strengths and attack styles, but its key differentiator is an RPG-like level system that makes your weapons increasingly powerful. The game's finely tuned challenge, flashy visuals and ability to upgrade your weapons to absurd levels make it an excellent stepping stone between earlier, simpler shoot-em-ups and the more complex games that followed from Cave and others.
Dogyuun features many elements common to Toaplan's shoot-em-ups, including brilliant visuals, inventive weapon options, striking boss designs and intense gameplay. Players are charged with bringing the fight to a race of alien robots who have taken over the planet Dino, piloting Sylfers attack fighters that can combine (if there are two players) into a single formidable (but vulnerable) ship. Though some have complained that the game put too much of an emphasis on visuals over gameplay (as some previous titles had been criticized for the opposite balance – you can't please them all), the game strikes an enjoyable balance between earlier Toaplan titles like Truxton and the dizzyingly-complex games the team would later create at Cave.