Metal Slug
Upon their initial appearance, both "Metal Slug 2" and "Metal Slug X" received generally positive reviews. Many of the subsequent ports and re-releases have received mixed reviews. For example, the iOS version of "Metal Slug 2" holds an aggregate score of 77% on GameRankings, based on 5 reviews, and 76 out of 100 on Metacritic, based on 6 reviews.