Start screen and game genres
The first screen you see when you run Arcade Game Studio is the screen.

Press [F10] to change screen mode, as all games are 256*256 pixels, ARGS workspace must be pixel perfect accordingly to this resolution so you can get a black zone on top and bottom of the screen. Press [F11] to switch between windowed or fullscreen. Press [F9] to save a screenshot.

Some screen modes will look the same, this is due to that in some cases on the screen you could experience some annoying lines on the backcells of the stage, if this happens try diferent screen modes to select a valid one.

Select to start your first game, a file wizard will show up to save your project file (can be diferent from your game name), I recomend to create a new folder for your project because a each project will create the following folders: actors, sounds, sprites, stages and tiles besides general files in the main directory.

Once you have saved your project you will be asked to select a game genre / button set.

Arcade Game Studio actually supports several genres, each designed with a specific mechanics, but with enough freedom to create complitely diferent and original games.

Let's take a closer look to this genres, also take note that this is a my particular view of arcade genres:
Scrolling Shooter
Genre where the player moves upward along the game stage (vertical Shooter) or rightward (horizontal Shooter), the screen movement (scroll) is automatic, and the objetive usually is to get to the enemy boss at the end of the stage.

Select this genre to make games similar to 1942, Xevious, Flying Shark, Raiden, Gyrodine, Gunsmoke (vertical), or Scramble, R-Type, Side Arms, Gradius (horizontal).

If scroll is disabled then we can get to make a classic Shoot'em-Up style game similar to Space Invaders, Galaxian or Galaga.

Also with some workarround tricks you could get to make games similar to Arkanoid or Road Fighter.
Genre where the player moves freely arround the stage, stage scroll is forced by the player, you can fix the stage movement vertically or horizontally so player can only move upward along the stage (Commando) or rightward (Jail Break), in this case the objetive usually is to get to the enemy boss at the end of the stage.

Select this genre to make games similar to Gauntlet, Commando, Jail Break, Ikary Warriors, Mercs or Shockway Troopers.

Is also perfect to make classic screen by screen games similar to Berzerk or Robotron.
Genre where the player has a 4-Way movement, stages are screen fitted and usually is a 'trap the hero' game.

Select this genre to make games similar to Pac-Man, Eyes or Bomberman for example.
Genre where the player is right-left faced, moves freely arround the stage and a gravity effect interacts with the actors, stage scroll is forced by the player.

Player has other movements aside from moving left or right, like crouching, jumping or climbing ladders.

Select this genre to make games similar to Ghosts 'n' Goblins, Contra, Black Tiger, Toki, Sunset Riders or why not Metal Slug.

With this genre and good knowledge of the program you could even get to make fighting games similar to Kung Fu Master, Shinobi or Dragon Ninja.
Other genres
Although the above genres cover a great range of the 80's arcade games, there are other genres that may be added with time, but I won't make any promises about it, this include 3rd Person Shooter games like Cabal, Beat'em-Ups games like Final Fight or Fighting games like Yie Ar Kung-Fu.