Metal Slug Defense (iOS, Android) brings SNK’s classic franchise to mobile devices with a strategy twist and a hint of frantic tapping. True to its name, the game can be difficult; and freeing captured POWs (prisoners of war) is the primary difficulty hurdle in this F2P title.
This may not be the style of Metal Slug game fans of the series are used to, but it plays well and does justice to the Metal Slug name despite the genre shift for mobile platforms.
Saving POWs is different this time around to go along with the strategy gameplay, and amassing them provides a number of benefits. We’re going to into why you should free them, and some tips on how to do so.
Why should you free captured POWs?
The game’s actual campaign isn’t that long, but some players may have a tough time pushing through the last stages. POWs provide spanning buffs that can help in these stages, and are necessary to be competitive in the game’s Wi-Fi VS. mode.
Going out of your way to free POWs is not required to complete the game’s campaign, but going after a few buffs will make things easier should you be having difficulty finishing the game.
Once you complete the campaign, all you have left to do in Metal Slug Defense is compete in Wi-Fi VS. mode and collect every POW. Neither one of these tasks are easy.
What buffs do POWs provide?
POWs captures can give you buffs in just about every area, from unit attack damage to maximum sortie points. Here are the current benefits to capturing each area’s POWs. Do note some of the wording in-game for these buffs is a bit off, so I will be listing them in my own words.
The first map is the one found to the left in stage selection, and the second is found to the right. The second map’s POWs include some characters from another popular SNK series, King of Fighters. The levels on the second map are much more difficult than those of the first, and are best done with units above level 15.
First map’s POWs
- Level 1 (Marchrius Dennis Rossi) – Increases AP accumulation in combat
- Level 2 (Tarmicle Roving III) – Raises maximum AP value
- Level 3 (Fiolina Germi) – Reduces production rate in combat
- Level 4 (Eri Kasamoto) – Increases MSP rewards
- Level 5 (Gimlet) – Raises base site HP
- Level 6 (Red Eye) – Increases AP gains from defeating enemies
- Level 7 (Trevor Spacey) – Increases unit HP
- Level 8 (Nadia Cassel) – Increases unit attack
- Level 9 (Walter Ryan) – Increases Metal Slug attack
- Level 10 (Tyra Elson) – Increases Metal Slug charge speed
- Level 11 (Rumi Aikawa) – Increases maximum sortie points
- Level 12 (SV-Camel) – Obtain SV-Camel unit
- Special level 1 (Abul Abbas) – Obtain 3-Ton Utility Truck unit
- Special level 2 (Allen O’Neil) – Obtain Di-Cokka unit
- Special level 3 (Donald Morden) – Obtain NOP-03 Sarubai unit
- Special level 4 (Mars People) – Obtain Hopper Mecha unit
Second map’s POWs
- Level 1 (Ralf Jones) – Increases AP accumulation in combat
- Level 2 (Clark Still) – Raises maximum AP value
- Level 3 (Whip) – Reduces production rate in combat
- Level 4 (Leona Heidern) – Increases MSP rewards
- Level 5 (Utan) – Raises base site HP
- Level 6 (Hyakutaro Ichimonji) – Increases AP gains from defeating enemies
- Level 7 (Lilly) – Increases unit HP
- Level 8 (Cynthia) – Increases unit attack
- Level 9 (Mary) – Increases Metal Slug attack
- Level 10 (Heidern) – Increases Metal Slug charge speed
- Level 11 (Madoka Aikawa) – Increases maximum sortie points
- Level 12 (Zombie Marco) – Obtain Zombie Marco unit
- Special level 1 (Abul Abbas ) – Obtain Abul Abbas unit
- Special level 2 (Allen O’Neil) – Obtain Allen O’Neil unit
- Special level 3 (Donald Morden) – Obtain Donald Morden unit
- Special level 4 (Mars People) – Obtain Mars People unit
(Note: Special levels appear rarely and must be completed quickly once they do.)
It’s not hard to see why you would want these bonuses. The trick to obtaining them is to free at least one POW per stage within a level. With each POW you free, the higher increase to that area’s buffs you obtain.
Let’s use Level 2 as an example of how the buffs scale with the amount of POWs you’ve freed. If you save only one POW in each of Level 2’s four stages, you will see a 66% increase in your maximum AP. As you free more within a level, you will reach a 100% increase in that level’s POW ability.
How do you free captive POWs?
Running from stage to stage trying to free POWs ended up being my primary timesink in the game, and it will likely be yours too.
In order to save a captive POW, you must complete a stage as quickly as possible. This means spamming units and taking down the enemy base quickly, without making many mistakes.
Some stages only have one POW, while others have 2 or more. You can free any number of the available POWs in a single run, provided you are fast enough. The more there are for you to save, more difficult obtaining the last one will be.
Unfortunately there is no sort of visible in-game timer, so the exact time requirements are a mystery. That said, having obtained every POW in the first map sans two special stages, I can confirm saving POWs is based on stage completion speed.
Going on the hunt for POWs requires a more in-depth knowledge of your available units than running the campaign because you need to determine which units are best for reaching the enemy base quickly within a stage.
Two units I can say I use frequently when seeking POWs (but rarely in the campaign) are the Soldier and the similarly grenade-happy Rebel Infantry. Both of these units are cheap on AP, have very fast production times, and do area of effect with their grenade skills.
When you run into a stage you just can’t seem to unlock even the first POW in, consider the types of units being thrown your way, and the speed at which they’re coming. Consider the following points:
- Do you need to need to call for supplies (increase AP production) at the start, after your first unit, or ever?
- How quickly do enemy units begin to flood your way?
- What types of units are being deployed by the enemy? Humanoid, mechanical, or something else? What are their stats? You can see most units within the game’s shop for stat information.
- Is your deck in an easy to use order?
- Are the units you have in your deck going to be effective against the enemies in the stage you’re aiming for?
- Would opening up a buff from another level give you a much-needed boost to complete the one you’re currently focused on?
Along with the above, you must also make sure you are:
- Using unit skills as soon as they can reach something your units can’t kill quickly with standard attacks.
- Constantly producing units, or saving for one in particular that will make your job easier.
The hunt for POWs includes a lot of frantic tapping — both deploying units and setting off skills. Always use skills to kill tough enemy units and break down the enemy base faster. You never want to be sitting and waiting for something to happen.
Units, AP, attack type, and other things to bear in mind
When looking at your units in the Customize Units screen, be sure to pay attention to their standard and special attacks’ targeting and range.
- If an attack says single, it will only hit one target at a time. An example of how “one target at a time works” lies in Eri, who’s laser special is technically single-target but can hit multiple enemies should they die one by one to her blast.
- If an attack says spread, it will hit everything in range at once. Tarma is the easiest unit to see how this works, as his shotgun range is short but can do damage to multiple enemies stacked directly in front of him.
- Each attack or special has its own range, regardless of whether it’s listed as long or short in their stats. This means all short attacks will not have the same range, nor will all long attacks. The easiest way to get used to this is by testing out each unit.
Along with all of the above, sometimes it’s just better to use cheap, low-power units to wear down the enemy base with specials. As mentioned before, Solider and Rebel Infantry units are valuable assets when seeking POWs because of their cheap cost, fast production, and AoE grenade specials.
If you are at the enemy base and units keep spawning, AoE special attacks will do damage to the enemies as well as to the base itself. This is why units with spread specials are valuable assets when hunting for POWs.
Example strategy for early POW missions
One strategy that has worked for me in several low-level stages is as follows:
- Wait until you have 60 AP and send out a Marco
- Wait until you have 70 AP and send out Eri
- Wait until you have 75 AP and send out Fio
- Send out nothing but Soldiers and Rebel Infantry from then on
- Use all special attacks as soon as they are available and enemy units are in range
This is a very simple example, but led me to a speedy POW-saving victory time and time again in the first map. You must spam your skills to make this work, and you cannot stop producing Soldiers and Rebel Infantry until done.
Notice I did not mention to upgrade your supplies, which means your AP is locked at your standard accumulation rate. Getting map 1’s Marchrius Dennis Rossi (level 1)’s POWs will help you accumulate AP without needing an early supply upgrade. The Development Speed level in the Home Customization menu will help as well. If you absolutely need to upgrade your supply acquisition, do so after sending out your first couple Soldiers/Rebel Infantry.
Hunting down POWs is very much Sortie Point-intensive. While the most obvious solution to this is to pump money into your Sortie Level in the Home Customization screen, the best course of action is to tackle level 11’s Rumi Aikawa POWs. The stages within her level are not too difficult, and if you’ve been upgrading your Sortie Level, her buff can push your Sortie Points well above 200.
Naturally, you will want to hunt down map 2’s level 11 (Madoka Aikawa) for an extra boost later down the line — but work on Rumi’s early on to give yourself some more chances to obtain those POWs.
Never leave a stage without finishing
Pushing through a stage even though you know you won’t get a POW can be a downer, but those Metal Slug Points you get for level completion are no joke. Always finish stages to get that money and put it into the units (or Home upgrades) you feel are most needed for the stage you are trying to get POWs from.
Keeping your units up to date with the latest in leveling technology (aka, the highest level available at the time) is a huge help to finishing levels faster, and hence collecting POWs. Aside from this somewhat obvious fact, some Home upgrades are essential as well.
Some Home upgrades are more helpful for speedy completion than others. The most useful are as follows:
- Sortie Level – This increases your Sortie Points value, and as such is one of the most important to upgrade when you can. That said, the increase from this is best paired with Rumi and Madoka Aikawa’s POW buffs.
- Development Speed – This increases the rate at which you accumulate AP. A must-have, and should be upgraded whenever possible.
- Production Speed – This increases the rate at which you can put out the same unit in a stage. For example, someone with a Production Speed level of 10 will be able to put out two Marcos faster than someone with a Production Speed level of 2.
- MSP Gain – This increases the amount of MSP you get per stage, making it easier to upgrade your units and Home. This may not be as important as the three upgrades listed above, but it is still essential to keeping a good pace as you progress.
- Destruction Bonus – You obtain more AP from killing enemy units as you level this, making it useful but not essential. I let this sit at level 5 for a long time before putting more money into it.
While the other Home upgrades certainly have their uses the ones listed here are the best for POW hunting. You need to get units out as quickly as possible, and the upgrades above are great help with that.