Do you remember those old game cartridges for systems like the Atari 2600 or the Nintendo Entertainment System which had multiple games on them? Now what would happen if such a cart would go corrupt and the system would get confused with all the info on such a cart? Well normally, it just wouldn't work but in ROM CHECK FAIL this idea is stretched to make a little game out of it.
The object of the game is to score as much points as possible as you destroy all the enemies on every level, each of which consists of 1 screen. However, the way you do this will change every few seconds or so. At one point you could be playing as Super Mario jumping and stomping on the ghosts from the Gauntlet series of games on a pac-man background while there is a tune playing from the Metroid games. Then after a few seconds everything gets distorted and BAM! Now all of a sudden you're playing as Link from the Legend of Zelda, slashing Space Invaders as they swoop downwards on a Spy Hunter background while the Bubble Bobble theme is playing. It's total chaos, and you'll never know what combination you'll get next.
As all the enemies are destroyed you go on to the next level. This means another amount of enemies and a different level layout. As the game rules and graphics might change any second, the level borders and amount of enemies are all set per level. This can mean disaster if you get turned into the wrong player character at the wrong spot, since they all control differently and try to emulate the original moves of the characters. If you, for example, change into the ship from Space Invaders at the top of the screen then you'll have a problem, since that ship can only go from left to right and shoot upwards. So sometimes you'll get into situations in which you just cannot defend yourself and this bit of randomness can surely be annoying. When you finish a level just when the screen starts to get distorted again, the distortion will pause and will remain this way until the next distortion. This will look very weird in most cases and it makes text (like your score) impossible to read. I'm not sure if this was done intentionally, but it does look neat and adds some charm to the game.
The controls feel a bit slippery on a lot of the characters. Mario and Pac-Man feel pretty much as if they're on ice and you can easily run into something by accident. While others, like Link, don't have this issue at all. It just ends up that some things, control wise, might feel off on certain characters compared to how you used to play them originally. Also enemies are sometimes a bit off. Some enemies don't seem to have been programmed with their unique behavior and just use the one of the enemies that were in their place before. The asteroids are a perfect example of this. If space invaders get turned into asteroids they just keep on moving from left to right, if they were stationary block before they will be stationary asteroids.
This won't be a game you'll get back to often, it's just not fun enough to keep playing and with the amount of randomness involved it's not a great game for competitive high score beating. However, this game is fun for a while or maybe in short bursts. It's a real novelty and in itself it can be a lot of fun to just see what parts of the game you recognize from older games. There are plenty of sprites, backgrounds, music and victory screens (which you see if you die after level 20) to give anyone who grew up in the 80s a nostalgic kick.