The tags Score Attack and High Score feel really similar to me. Maybe they should be merged? Or, at least, the difference should be clear.
Viewing post in Tag merges and suggestions
Same with Leaderboard.
We have an online-leaderboard tag as well, but I feel like that one is more clearly distinct because being able to compare scores worldwide is a separate enough feature.
When I try to look up Score Attack on Wikipedia I get a redirect to Score (game), which contains a paragraph on High Score but the actual term Score Attack is nowhere to be found. So the duplicates should be merged into the High Score tag.