Contra: Operation Galuga – How to Maximize Credits in Arcade Mode

This guide will tell you how to get the most credits from a single run, for up to 45000 credits per hour!



This guide will explain what actions in Arcade Mode award credits and how to maximize credits gained from your runs. In a perfect run through the game on the hardest settings, you can get up to about 45000 credits, but even when taking the easy route, you can make 20000+ credits within under an hour. Keep in mind that this is a guide for Arcade Mode only – credits calculation in Story Mode is very different. Also, while I consider this guide to be mostly complete, there are still a few more details I haven’t figured out yet, so I might update this in the future.

Overview of credit sources

You gain credits by:

  • Killing enemies (your score gets converted to credits)
  • Starting a stage
  • Collecting a weapon
  • Upgrading a weapon to level 2
  • Using an overload
  • Gaining an extra life
  • Killing the final boss

At the end of the game, your credits will be multiplied if:

  • You finished several stages in a row
  • You played in 1-Hit Kill mode


If you finish several stages in a row, your bonus credits will get multiplied by the number of stages you completed. For example, if you get your first game over on stage 5, you will receive a x4 multiplier on the credits you received so far, and if you get another game over on stage 5, you will receive no multiplier at all. If you make it through all 8 stages in one go, you will receive a x8 multiplier.

If you play on 1-Hit Kill mode, you will receive a “danger bonus”, which means all your bonus credits will get multiplied by 2.

You can receive both multipliers at the same time, meaning the best you can achieve is x16.

Killing enemies

The score you accumulate for killing enemies gets converted to credits by dividing it by 1000, rounding up the result. This means if you take your time to kill most the enemies in the game and finish with a score of 350,000 you’ll end up with a measly 350 credits. These are your base credits. Credits from all other sources are considered “bonus credits”. It is important to know that base credits will NOT get multiplied by any bonus multiplier you achieve – only your bonus credits will get multiplied. When maximizing your credits per run, base credits will be less then 1% of your total credits, so farming respawning enemies for score is pointless and if you want to increase your credit per hour ratio, you should focus on skipping enemies and getting through the game faster while aiming for bonus credits through the methods described below.

Starting stages

Every time you start a stage, you gain a small amount of credits just for entering. On a game over, you will get the credits for the current stage again if you continue, but not for any previous stages. The amount of credits you get per stage vary on the difficulty mode you’re playing – 20 credits on easy, 25 credits on normal, and 35 credits on hard. Assuming 1-Hit Kill mode and getting the x8 muliplier, the difference between easy and hard is 1920 credits.This is actually the ONLY difference regarding credits between difficulties, so if you can run through the game much faster on easy or if you’re not sure if you can finish the game on normal or hard without a game over, it will probably be way more effective to play easy mode to farm credits.

Collecting/upgrading weapons

Every weapon you collect is worth 1 credit. Every weapon upgrade you get is worth 5 credits instead (to clarify: when you collect an upgrade, you are not getting 1 credit for collecting the weapon and 5 for the upgrade – it’s 5 in total for collecting the second level).

This only applies to new weapon drops, so when you drop your old weapon by collecting a new one, you can’t abuse this system by collecting the dropped weapons over and over again.

If you are using the Auto-Levelup perk, you will receive 5 points for EVERY weapon you collect, making this perk by far the best option to maximize credits.

If you collect the same weapon you already got on level 2 and already got a weapon in your second slot, you will only get 1 credit for collecting the weapon again – this is also true when using the Auto-Levelup perk, so when using this perk, make sure you never carry the same weapon twice. This way, you can always collect a new weapon.

Also make sure to have an eye on your bonus pod meter. This meter fills by killing enemies and by using overloads. Every time the meter is full, you want to call the pod as soon as possible. Every enemy you kill and every overload you use while the meter is full are wasted and might lead to one less bonus pod per stage. The bonus pod meter does NOT carry over to the next stage.

Using overloads

Every time you use an overload, you get 5 credits. This will be one of your main sources of credits, next to collecting level 2 weapons with the Auto-Levelup perk. In most cases, you will want to use one weapon slot for your weapon of choice and the other slot to just collect new weapons and then instantly use their overload, so you don’t miss out on any weapon drops. This is especially true on the bike stages, where you can easily miss pods. On those stages, you’ll want to remember all the places where two pods will spawn at the same time, so you can free both your weapon slots beforehand.

Also make sure not to waste weapons by collecting the same weapon twice – not only will you receive only 1 credit for the weapon (as explained above), you will also miss out on one overload.

The same is true for level 2 upgrades IF you’re playing with Auto-Levelup and Healh Meter. If you get hit and lose your weapon upgrade, overload the weapon before you collect the same weapon again, as the new weapon will just upgrade your current weapon. You need to do this because when playing with Auto-Levelup, overloading a level 2 weapon will consume the entire weapon, while without the perk, overloading would only downgrade your weapon to level 1.

Remember that every time you die and lose a weapon, that’s one overload you’re missing out on, so if you tend to die a lot, it might be worth using the Weapon Retention perk.

Finally, every overload you use fills your bonus pod meter by a large chunk, which means when overloading every weapon you get you will also receive many bonus pods, which in turn translates to more credits for weapon pickups and overloads.

Gaining extra lives

Every extra live you gain is worth 2 credits. Strangely, this includes starting lives. This means playing on an easier difficulty or unlocking more lives in the perk shop increases your starting credits. So on easy you start out with up to 20 bonus credits, while on hard, you start out with only up to 10 bonus credits. Considering multipliers, this ends up as a total of 160 additional credits on easy, which is another reason to farm credits on easy. Using the Konami Code perk also counts towards this, so this will grant 62 credits (992 with multipliers) regardless of difficulty mode. Of course, you would have to subtract the number of credits you would have gotten from your base lives from this number to get to the actual gain this will give you. It’s not really that much in total, but if you need more lives to finish the game in one go anyways, this becomes an obvious choice for your second perk in 1-Hit Kill mode. In Health Meter mode, you might still prefer HP Boost+ or Weapon Durability. During a full run, you will usually receive about one extra life per stage if you kill everything, so that’s another 16 (256 with multipliers) credits per run.

Killing the final boss

The final boss is the only enemy in the game that rewards bonus credits, and it rewards a lot. The number of credits awarded varied for me on every run, and I could not yet figure out what’s the reason for this. I’ve seen numbers between 480 and 487 for this boss, so whatever variance there is, it seems to be pretty negligible. Assuming 480 credits, that’s 7680 credits with all multipliers just for defeating the final boss alone! Combined with receiving the x8 multiplier on the rest of your credits, it’s well worth it to finish the game in one run, so much that on a single game over, you might just restart the game.

Optimal setup

For your optimal setup, you definitly will want to run the Auto-Levelup perk. No other perk or combination of perk comes even close to what Auto-Levelup provides.

As explained above, Konami Code can be very helpful with surviving until the end and also gives a few extra credits just for taking the perk. If you play on easy with 9 lives, Konami Code is worth 672 extra credits.

Mercy Pod basically turns each of your lives into another 10 credits. This might sound like a huge bonus, but is actually worth less than Konami Code. When playing the way I described in this guide, you will fill your bonus pod meter very quickly, which means every time Mercy Pod triggers, you waste the amount of your pod meter you have already collected, which reduces the overall value of Mercy Pod. If you can manage to finish the game without losing a single life and then blow all your lives for Mercy Pod just before the end (or do the same thing at the beginning of the game), this would net you the full value of the perk. If you play on easy with 9 lives and receive 8 extra lives during your run, that’s 554 credits with multipliers – meaning even under optimal conditions, it provides less credits than Konami Code.

As both of the Konami Code and Mercy Pod perks don’t really contribute THAT much of a bonus, you might also consider just taking whatever perk helps you best to complete or maybe just speed up your run.

Another point to consider is whether you want to run 1-Hit Kill mode. The x2 multiplier on the credits is obviously gigantic, but if you can’t make it to the end of the game consistently, it might be more efficient for you to do two runs with Health Meter instead. If you got one failed run and one completed run in 1-Hit Kill mode, that’s still better than two Health Meter runs, but if you fail two 1-Hit Kill runs in a row, that’s the point at which Health Meter runs become more efficient.

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