In it, villains such as Dr. Wily and Sigma have teamed up thanks to a Time Crash and captured all the Mega Men, putting Crossover World in jeopardy. Dr. Light and Dr. Cossack get to work producing a Reploid to stop this - OVER-1, a production model.
OVER-1 is able to collect Battle Chips (no relation to the Battle Network objects of the same name) to increase its Battle Memory, which will allow it to mimic the abilities of the Mega Men before it. Its job is to save the missing heroes and Crossover World in general.
In the grand tradition of most iOS titles, you can buy certain items instead of collecting them. You may also summon a friend's OVER-1 for use in battle.
This game provides examples of:
- Abnormal Ammo: Arcade Man, a new character in this game, fights by shooting game sprites at OVER-1.
- Animal Motifs: OVER-2 looks like a combination of a wolf and an eagle.
- Art Shift: While the game incorporates a large amount of art from other Mega Man series, the "in-house" art style is heavily influenced by Mega Man X. Every now and again you'll find Xover-unique art of other series' characters.
- Ascended Meme: Airman ga Taosenai, the song that single-handedly turned Airman into a Memetic Badass, is part of the game's soundtrack.
- Badass in Distress: The protagonists of each Mega Man series are trapped beyond space and time by the forces of evil, and it is up to the Reploid OVER-1 to combat this crisis.
- Bait-and-Switch: Capcom announced an anniversary surprise for the game using a piece of Legends' artwork...and it turned out the surprise was original robot masters from the classic series.
- The Bus Came Back: Kalinka returns, now 14, with longer hair and wearing light blue.
- Bribing Your Way to Victory: You can purchase certain items, though you can also obtain them the normal way.
- Character Customization: One of the game's saving graces is the fact that Xover can be customized.
- Composite Character: In the 15th Anniversery bonus world, three bosses fought previously are given the palettes and powers of others: Fire Toad Man, Wood Guts Man, and Electric Shadow Man
- Cut and Paste Environments: All the levels in a world use the exact same background and the same two to four enemies over and over. The background and enemies change only about every seven levels.
- Elemental Rock-Paper-Scissors: A holdover stable from Star Force and Battle Network.
- Exactly What It Says on the Tin: Crossover World.
- Expy: Among the Battle Tower bosses is Nero L, who appears to be equal parts Bass, and equal parts Vergil.
- Fanservice: The art the series has produced includes pictures of past Mega Man heroines (including Luna and Tron) in swimwear, mostly bikinis.
- Fake Crossover: Rockman Xover is described as a crossover involving all seven Mega Man subseries. However, the game makes no presence of the subseries' respective main protagonists even though the premise revolves around saving them after they are trapped beyond space and time by evil, and Kalinka is one of the very few characters with a direct appearance to indicate that there's a crossover occurring at all.
- Forced Tutorial: Kalinka teaches you how to play when you first start, in case you didn't know already.
- Girlish Pigtails: Oro S sports twintails shaped like lightning bolts.
- Jack of All Trades: OVER-1, basically.
- Multiform Balance: One of the main draws of the game was the variety of armors Over-01 could collect, which each came with different stats and Battle Memory layouts.
- No Sidepaths, No Exploration, No Freedom: An on rails-platformernote until the boss. Literally all that Mega Man can do is Jump 'N' Shoot.
- Although this might not be the case anymore, early screenshots have shown an AutoPlay button (for the normal sections) and a Skip button (for the boss battle). These features imply that it could have been possible to complete stages and bosses with a push of one button. Alternatively, these buttons function like the Super Guide.
- PAL Bonus: The Taiwanese version only had an exclusive boss, Fel Reaver, although he's just a modification of ElementMan.exe. The Taiwanese version also had a special shop in which collectable gems could be traded for useful items.
- Power Copying: OVER-1 copies the powers of other Mega Men, meaning he's Power Copying the Power Copiers!
- Recycled Soundtrack: The themes of Central Highway and the boos battle of Mega Man X appear here.
- Red Eyes, Take Warning: Oro S.
- Scunthorpe Problem: A non-innuendo one with Rockman XOver.
- Snipe the Sky: MegaMan.EXE is shown pointing his buster upward in the above art.
- Unexplained Recovery: Wily and Sigma team up again...although Wily has the excuse of being alive during the X series somehow, Sigma was Killed Off for Real at the end of X8.