Zeroptian Invasion

Welcome to the walkthrough for Zeroptian Invasion.

Like other offerings from Ratalaika Games, this game is an extremely quick completion. You can easily clear it in under an hour with some basic reflexes and familiarity with shooter games. You only need to beat the first 7 levels of the game which will give you all of the achievements in the game so long as you also die once (which you probably will). The game itself is a clone of Galaga and the minimalist/retro art style is done in a similar fashion. The gameplay is very simple, with you only being able to move left and right and fire a bullet. You'll be dodging enemies and enemy fire while trying to take them out.

That's really about it.

The game is very simple, with your ship only being able to move left and right, and firing a single bullet at a time. It is mostly just prioritizing dodging bullets over hitting enemies. However, you can make it a little bit easier on yourself by knowing the mechanics a bit and farming power ups.

  • You can only fire a single bullet a time and you can't fire the next one until your bullet either leaves the screen or hits an enemy. Therefore taking the time to shoot accurately means you'll actually be able to fire more often and kill things more quickly. That being said, avoiding bullets and just blindly firing is relatively effective while there are lots of enemies on the screen.
  • In general the game is more about pacing than quick reflexes. The speed you, the enemies, and bullets move at lends itself to slightly planning ahead and lining up shots.
  • When you start to thin out the enemies they will begin to move faster. When there is about 5 or so left you'll notice they move about twice as fast. When there is only 1 you'll notice they move even faster.
  • The enemies move left or right as a group and once they hit the edge of the screen they'll move down a row. You can make their path longer by killing the enemies on the outside of the formation first. A small group (or ideally a single column) will have to move across the entire screen before moving down.
  • There are three power-ups in the game: (P) power, which gives you two shots instead of one, (S) shields, which absorbs a single hit (essentially a free life), (=>) arrow, which makes you move faster. They're all obviously useful in their own way. Power-ups drop from a UFO which periodically spawns at the very top of the screen. Shoot it down and grab the power-up as it falls down. If you already have a particular power-up you'll get 500 points instead.
  • You can, and should, farm power-ups. To farm power-ups, simply kill most enemies on a level. In particular, I recommend getting them down to about 6 enemies so they're not moving faster and in a tight column so they take the longest to travel across the screen. You'll also want to kill the topmost row first in the first world since they fire diagonal projectiles aimed at your position. Then just avoid the group and its bullets until a UFO spawns, kill the UFO, and grab the power up. Repeat until you have all 3 power-ups.
  • You get a checkpoint after every boss. The first two bosses are on levels 3 and 7. Therefore if you lose all your lives after beating the first boss, so long as you continue you will start on level 4. You only really have to be able to beat a world at a time on your 2 lives. You can theoretically get all the achievements on a single playthrough, but you can also continue as many times as you want.
  • Most simple enemies are worth a 100 points. Most of the "advanced" (i.e., diagonal shooting/top row) enemies are worth 200 points. In the second world the enemies that take 2 hits to kill are worth 500 points if you kill them before clearing their columns (and sometimes you get 500 points regardless). In general, since you must clear a whole world on a single continue, you will get all the score based achievements in that go. So you do not and should not have to worry about your score really.
  • For beating a boss/clearing a world, you get an accuracy score bonus. This is purely your accuracy percentage * 100. So if your shots were 52% accurate, you will get a bonus 5200 to your score. This bonus, all the enemies in the world, and the boss guarantee you will get 10000 points minimum for beating a world. As this is the highest number of points required for an achievement, you don't need to worry about getting a good score. You only need to worry about beating the world.
  • You get an extra life at 10000 points. You're pretty much guaranteed to get this while clearing a world.
  • Big WARNING: if you let the enemies get all the way down to your level you'll die automatically! Don't let this happen. Kill the enemies before they get too low.

Again, the game is very simple. Move left and right to avoid enemies and enemy fire, and fire to kill all the enemies. The first world consists of 3 levels, the second one of 4. You get a checkpoint after level 3. You can continue as many times as you want. You only get 2 lives, making the shield power-up a very powerful way to extend your life.

Aside from dying, the other achievements are all story-related or score-based. Between killing 3 levels' worth of enemies, the boss on the last stage, and the accuracy bonus you get, you're pretty much guaranteed to get all the score-based achievements for just clearing a world. Therefore, an argument could be made that all the score-based achievements are also story-based because you cannot not get them while clearing a world.

So your approach should be just to focus on clearing the first two worlds. Do farm power-ups to make your life easier as described in the hints and tips section.

Level 1 (L1)

This is a standard Galaga-like setup. You'll have a bunch of enemies and some shields that will slowly take damage and disappear. Simply whittle the enemies down to a few, and then farm power-ups before clearing the level to set yourself up. You can shoot down most projectiles in the game, but it's generally safer and easier to just avoid them.

There will be three rows of enemies. The enemies in the first 2 rows can only fire straight down and are worth 100 points each. The enemies at the very top row are worth 200 points each and will fire a diagonal shot aimed at where you are currently standing. You'll have to move out of your current location to dodge it.

You get 3 obstacles that act as shields. These will take damage over time and eventually disappear so you do want to take out enemies relatively quickly.

You should farm power-ups here. I'd recommend killing the top row of enemies since they fire the shots most likely to kill you and leaving some of the lower row enemies alive.

If you die you'll get:

Welcome in Zeroptian Invasion
Welcome80 (80)
Die for the first time
  • Unlocked by 3,126 tracked gamers (100% - TA Ratio = 1.00) 3,133

Simply killing all the enemies on the level guarantees the first score based achievement:

Don't give up in Zeroptian Invasion
Get 1000 score
  • Unlocked by 3,117 tracked gamers (99% - TA Ratio = 1.00) 3,133

When you grab your first power-up you'll unlock the following achievement:

Boosted in Zeroptian Invasion
Boosted80 (80)
Get a power up
  • Unlocked by 3,103 tracked gamers (99% - TA Ratio = 1.00) 3,133

Level 2 (L2)

Another standard Galaga-like setup. Same strategy as the first level.

You'll only get 2 obstacles that act as shields. There will also be 4 rows of enemies. The first 3 can only fire straight down. The topmost row has the diagonal shooting ones.

Simply killing all the enemies on the first two levels guarantees the second score-based achievement:

Good job in Zeroptian Invasion
Good job80 (80)
Get 2000 score
  • Unlocked by 3,104 tracked gamers (99% - TA Ratio = 1.00) 3,133

Level 3 (L3)

A final level of vanilla Galaga-like setup. There's a boss at the end once you kill all the enemies.

Again you will have 4 rows of enemies with the first 3 rows shooting straight down and the top-most row firing diagonally. There will be just slightly more of them than in the last level. You only get one obstacle this time around, but it can't be destroyed... because it'll transform into the boss once all the enemies are dead.

The first boss is pretty straightforward. It will fly around in a vertical figure-8 and fire several projectiles at a time at you. There's an eye in the middle which you need to aim for in order to damage it. It'll take about 10 hits.

You're are also guaranteed to hit 5000 points during this level getting you the 3rd score-based achievement (as a reference, with a couple of duplicate power-ups I was at 6950):

Well done in Zeroptian Invasion
Well done81 (80)
Get 5000 score
  • Unlocked by 3,032 tracked gamers (97% - TA Ratio = 1.01) 3,133

For beating the boss and completing level 3 you will get the following achievements:

A hidden enemy in Zeroptian Invasion
Destroy the boss of the first area
  • Unlocked by 2,914 tracked gamers (93% - TA Ratio = 1.03) 3,133

Going forward in Zeroptian Invasion
Complete 3 levels
  • Unlocked by 2,912 tracked gamers (93% - TA Ratio = 1.03) 3,133

You'll get an accuracy score bonus at the end of the level as well. It's your accuracy * 100. So long as you get somewhere around 50%, you'll get 5000 points, or half the points for the last score related achievement. Combined with the guaranteed 5000 from the enemies from the first 3 levels, this should push you far enough to 10000 and the last score based achievement:

That will teach them in Zeroptian Invasion
Get 10000 score
  • Unlocked by 2,865 tracked gamers (91% - TA Ratio = 1.04) 3,133

Level 4 (R2)

You get a checkpoint here. If you lose all your lives, when you continue you will now start here.

This is a transitional/travel level setup. It's similar to the bonus levels from Galaga. Enemies will fly down in a group of 5 in set patterns. There will be 4 waves. You can kill them but don't have to. They do fire diagonal bullets aimed at your current location. They will eventually fly through the bottom of the screen and you'll complete the level regardless. You cannot farm power-ups on this level.

Level 5 (L4)

We're back to the standard Galaga setup again. And that will be the setup for the next 3 levels.

You get 2 moving platforms that serve as shields that will eventually be whittled down.

There are 4 rows of enemies. There are spiders that will shoot spiderwebs that don't actually hurt you (but do slow you down). You can't shoot spiderwebs down. The last row of enemies also now takes 2 hits to kill. However, all of the enemies can only fire straight down. In some ways this setup is actually easier than the enemies that fire at you. Depending on how you kill the top row of enemies (generally if you do it before clearing the column) the enemies will give you a bonus 500 points (not that you should need points anymore).

There will also be a random boomerang-looking projectile that zigzags in a column. It can be shot down for 200 points, but it's probably just easier to stay out of that column.

After completing this level you'll get the following achievement:

Excellent in Zeroptian Invasion
Excellent84 (80)
Complete 5 levels
  • Unlocked by 2,831 tracked gamers (90% - TA Ratio = 1.05) 3,133

Level 6 (L5)

You only get one moving platform to serve as a shield.

Again there are 4 rows of enemies. Same setup as the level before, just slightly more enemies.

Additionally, there's a column in the middle that will have falling rocks. You need to avoid these and they will block your bullets.

Level 7 (L6)

The final level you need to beat, and it has a giant spider web as its background. (A spider web in space... don't ask).

There is no obstacle for you to use as a shield, but the enemies start very far up and there are no hazards.

There are again 4 rows of enemies, but this time the enemies that take two hits are in the middle of the 3rd row. The enemies are also mostly spiders making it easy to use this level to farm powers ups. You should farm power-ups because there's a boss at the end.

Once all the enemies are dead, the boss will crawl up from the bottom of the screen. There will be three !!! indicating where he will spawn so you do not want to stand there. The boss looks like a bee/caterpillar hybrid (because bees/caterpillars weave webs) and it's a lot larger than the first boss. However, like the first boss it shoots a bunch of projectiles. Like the first boss the weak point is in the center, in this case the stinger. This boss will also spawn red orbs that will bounce around the entire screen. These can be shot down with 2 shots. I found it easier to just ignore them and take the boss out quickly. You'll have to hit the boss about 15 times to kill it. Once you do you'll unlock the last 2 achievements in the game.

A messy enemy in Zeroptian Invasion
Destroy the boss of the second area
  • Unlocked by 2,295 tracked gamers (73% - TA Ratio = 1.16) 3,133

Impressive in Zeroptian Invasion
Impressive234 (200)
Complete 7 levels
  • Unlocked by 2,294 tracked gamers (73% - TA Ratio = 1.16) 3,133

Congratulations on the 1000GS and another completion!

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