River Raid has no backstory. Everything is obscenely simple - you need to score as many points as possible by destroying enemy destroyers, helicopters, gas stations, balloons, tanks, planes and bridges.
River Raid is the most common flying shooter. The plane moves up the river, from one bridge to another, destroying them and everything that comes along the way. Do not forget about fuel, it runs out at the most inopportune moment.
River Raid was one of the best games for the Atari 2600, and the 5200 version is not much different. Naturally, the graphics component has been improved, fortunately, the hardware allowed. The enemies were joined by balloons and tanks firing from the shore. Sometimes, you can get double the fun by blowing up the bridge and the tank on it. I recommend.