The video game "Excitebike" was first released as an arcade game in 1984. It was soon ported to the fledgling Nintendo Entertainment System as one of the console's launch titles. This game ran on the Nintendo Vs. Unisystem hardware platform (and could run on the Dualsystem hardware as well). High quality ports like "Excitebike" are one of the reason the NES was so successful. Nintendo actually ported almost their entire arcade lineup to the NES, most of these were available at the system's launch. In fact, no system has ever had a lineup of launch titles to rival those of the NES.
Excitebike is a left to right scrolling racing game with a semi-isometric viewpoint. This was not the first game ever in this genre (that distinction belongs to the old Atari 2600 title "Grand Prix), but it is definitely the most fun. You control a motorcycle that races on a straight off-road course littered with obstacles (mostly ramps). You can race on five different courses, both by yourself and with computer racers. The computer racers move without rhyme or reason, and there appears to be an unlimited number of hem on the course, despite the fact that there are only three other racers with you at the starting line.
You control the action with a 4-Way joystick and two buttons. (The NES port uses an 8-Way gamepad, but it is still coded for a 4-Way controller, and actually feels slightly better with one). Your two buttons are "gas" and "turbo". They are both accelerator buttons, but the "turbo" one is faster and can cause your bike to overheat if it is used for too long. You can push up or down to change lanes, and pressing backwards will cause you to do a wheelie, which is usefull for going over some obstacles. When you are in the air (from a ramp or other jump), you can control the angle of your bike by pressing forward or back. The idea is to match the angle of whatever you are landing on, you will crash if you hit something at the wrong angle. Don't worry about that too much, as it soon becomes second nature.
The arcade version and the console version have identical graphics and control, but there are minor differences in the level sequences. In the console version you get to select if you are racing alone, or with computer racers, while it merely alternates in the arcade version. Both versions have exactly the same tracks, except that the arcade version scores them differently. The home version also included a track designer that was programmed to interface with a never released "Nes Memory Pack". Several early games (like Wrecking Crew), had the interface options to save to this non-existant hardware.
The arcade version ran on the Nintendo Vs. Unisystem hardware (or the more uncommon Dualsystem), and was usually purchased in kit form to retrofit an old Donkey Kong or Donkey Kong Junior machine. A few dedicated cabinets were made (mostly Dualsystem uprights and cocktails), but the conversion kit ones were the most common. Excitebike just used the plain Vs. platform with no add-ons. That means you can get a set of "Excitebike" EPROMs burned cheaply, and plug them into any pre-existing Vs. motherboard.
The cartridge version can be had cheaply in almost any used game shop, as it is one of the most common NES titles around. You should not have much trouble finding it.