Metal Slug Attack (Japanese: メタルスラッグアタック - Metaru Suraggu Atakku) is a tower defense game created by SNK Playmore for iOS and Android mobile devices. It was originally announced by SNK Playmore in November 2015, and then officially released for Android and iOS on 14 February 2016. The game itself is a sequel to Metal Slug Defense, featuring numerous improvements and brand new game modes.
The official time zone is GMT+9 (Japan Standard Time).
Much like its predecessor, at the core of this game is the 2D (side-scrolling, given the main series' style) 1-on-1 subgenre of tower defense/strategy, with 2 bases on either side of the level where units are spawned. The main objective of the game is to destroy the opposing base by any means.
Once the game begins, forces start accruing Action Points (or AP for short), which are used to produce units that automatically advance toward the enemy's base. They can either execute attacks, or construct objects that impede the opponent, support allies, or produce additional units at no cost. Paying Rumi Aikawa a certain amount of AP will improve the rate at which AP build up, as well as the maximum AP that can be stored a time. Additionally, destroying enemy units grants a small amount of AP.
Most combatants have both a standard attack (melee and/or ranged) and a special attack. When the unit is within range of an enemy, it will begin its standard attack. After a predetermined length of time, the special attack will become available, indicated by a light blue "aura" surrounding the unit, that is activated by tapping. After finishing the special attack, the unit will continue with its standard attack until the special attack is charged again. For an extra edge in battle the player can purchase Power-Ups.
Metal Slug Attack goes farther at allowing players to improve their units' effectiveness.
- Special Ops is a timed cooperative challenge consisting of 3 stages.
- Battle (unlocked at Level 3) is a competitive asynchronous multiplayer mode in which players attack each other and NPCs in pursuit of higher ranks and Battle Medals.
- Combat School (unlocked at Level 4) is similar to MSD's Mission game mode, sans predetermined unit decks. Missions differ each day of the week.
- P.O.W. Rescue (unlocked at Level 5) is a timed mode in which the player is tasked with completing a series of stages of increasing difficulty.
- Guild Raid (unlocked at Level 8) is a cooperative game mode in which players attack difficult targets spread across several stages.
- Online (unlocked at Level 10) is the equivalent of MSD's Wi-Fi VS and is the only real-time PVP mode available.
- Team Battle (unlocked at Level 20) is a competitive asynchronous multiplayer mode, similar to Battle but having to fight 3 different decks and requiring beating 2 out of 3 battles to win.
- Extra Ops is a limited time mode where various side stories from the Metal Slug lore appears as special events (complete with intro movies, and sometimes endings), clearing all stages will earn you the event unit, though that may be not the case, as the mode varies from each Extra Ops event, and the ways to earn extra prizes, such as MSP, Medals, Units, and so on.
- Another Story, added in the 2.0.0 update is where you can check out more of the backstory to MSA within certain characters and various chapters within the 5 factions. You can also earn previous EO unit parts/items along with exclusive units to unlock in this mode as well. Although, you can only have 3 chances daily to play in this mode. Chances are refreshed daily.
Economy Related Features
- Build Up is the equivalent of MSD's Customise menu.
- Mystery Crank is a gambling station.
- Daily Login gives rewards each day for logging in.
- Daily quests give considerable MSP and EXP rewards for activity.
- Quest gives primarily Medal rewards for reaching milestones.
- Mailbox is where automatic event rewards are stored until a player collects them.
- Free gives Medal rewards for watching advertisement, downloading apps and following steps.
- Extra Shop and Rare Shop (unlocked at Level 3) are occasionally unlockable via Attack!
- Shop (unlocked at Level 4) is always available.
- Treasure Hunt (unlocked at Level 9) is a bonus way of obtaining pre-determined Units for MSP.
- Mars Shop (unlocked at Level 15), added in the 1.8.0 update, a new shop appears where you can buy exclusive unit pieces or items within trading unit pieces after said unit has already been evolved to the Platinum level, and any overflow pieces can be converted to "Mars Points", piece currency as follows...Normal: 1/Rare: 10/Super Rare: 40 per piece.
- Dress Up, added in the 2.7.0 is a additional shop where you can purchase avatar icons, bases, and custom BGM you can set in-game, and in online. (Some are free, while the rest cost medals.)
- Message is the only means to communicate globally, with one's Guild, or with another player. It also notifies a player of being attacked or when a clan mate is requesting help with Special Ops.
- Event is where the developers post announcements.
- Ranking (unlocked at Level 10) (one for Guild mode and another one for Online mode, and even one for Extra Ops, the first being the Sol Dae Rokker themed event).
Differences from Metal Slug Defense
Although having the same core game mechanics as Metal Slug Defense, aside from introducing new features, Metal Slug Attack has changed how old things work in comparison to its predecessor.
- Multiple game modes with different rules, to the point that a busy person may find that there is too much to do.
- Units can be upgraded in various ways - from flat stat increase to learning special attacks and effects.
- Additional charged command abilities are available - aside from the charging self-destructing SV-001 there are Recovery and Reload powers to heal units and instantly charge special attacks respectively.
- AUTO mode in combat is always available and does not block manual production [added in 1.2.0].
- Introduction of the Guild System and means to communicate with other players.
- Daily Login contributes to one's VIP EXP.
- By requiring internet access the game prevents offline exploits (i.g. free level restart) but makes loading times between every single menu action preposterously longer. (Although, later updates make the load times noticeably shorter.)
- An unskippable tutorial holds a new player's hand through introductory missions and shows how core mechanics work.
- Although players can acquire Units not exclusively with Medals, the process of doing so is significantly prolonged and depends heavily on chance.
- Stock (fresh, non-upgraded) units have limited combat effectiveness.
- Only 5 out of 10 unit cards can be seen on the screen in combat at a time, as opposed to 6, hindering player performance.
Stacking units from one faction exclusively into a single deck no longer provides HP boost.[patched in 1.0.4]
- Searching opponents in Online by similar deck AP value is no longer possible.
- Metal Slug Attack was released as the official game for the series' 20th anniversary.
- Much like its predecessor, Metal Slug Defense, this game recycles assets (e.g. graphics, sounds, and music) from other games in the series. Some of game mechanics are an improvement upon concepts from Metal Slug Defense and Metal Slug Wars.
- Same as Metal Slug Defense, Metal Slug Attack also had their own storyline that filled the "Hole" between storyline in Metal Slug Universe.
- Upon changing the user's date and time in settings then visiting the "Customize Unit" menu, players are able to see the upcoming Extra Ops/Guild Ops units, rewards, and pickup unit. This can be also explained as the next extra/guild ops units are hidden until the current Extra/Guild Ops ends.