Space Invaders Infinity Gene

Despite the high TA ratios (and 6% completion rate) this isn't so bad with a bit of planning and practice. If you're going for this achv, you're probably going for the max so I'd say my first tip is that you do the other stuff first. Get used to playing on the higher difficulties, get decent at the game. I beat Challenge Mode on the second highest difficulty (very tough but you can keep continuing throughout) and went back to this achv and got it in two goes.

Like Myupyon says - Play on Easy with nine ships. Use the Field weapon. You can afford to lose a life or two before 5-1. I lost four lives in my successful attempt. There's no impossible bits in the game.

There's no easy way around this achv beyond that. You will have to earn it. What I did was play through the game, making a note of any dangerous parts. Practice the bits where you die. Learn to get past the Progressive UFO (level 4-3... the boss with the black and white stripe attack), AXON (level 4-6... he's easy when you know the pattern but will kill you quick if you don't) and CRAB (5-2).
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Walkthrough.

General tips: keep firing always (X or RT work as firebutton so hold one down constantly). You do more damage when staying still. Stay low and central unless the walkthrough specifies that you don't. Don't chase power-ups: once you have six you're maxed out, don't risk a life for another.


1-1 - just play and get power-ups
1-2 - same as above
1-3 - stay low! There are some horizontally moving enemies that can kill you.
1-4 - stay low because of armoured enemies
1-5 - easy
1-6 - easy. For the boss avoid the beams of light. When the boss actually appears, just don't stop underneath him and he'll die quickly.

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2-1 - not much danger. Stay low, when you see some lines coming from below, definitely stay low there. Stay central, before the boss some enemies arc up from the bottom left and right.
2-2 - one horizontal ufo to worry about - stay low - and make sure to kill the 8-sided enemies (they rise up and fire lasers across the screen. Easy boss (target the square at the end of the line, stop moving, no danger)
2-3 - stay low and START FIRING right away (you should always anyway). stay central and only go up - after horizontal bullets - to take out the 'classic' invaders who shoot lasers. Boss is easy, get close to negate him - with nagoya attacks (a defensive technique where bullets cant hurt you because you are so close) - or attack from the side (recommended).
2-4 - Sub-boss is the biggest danger so far (stay top corner level level with low side of boss - watch out for powerup ufos above, they can hit you if too high) afterwards, stay low and central (shouldn't need to move - danger above). Boss can be defeated from inside or outside his wireframe (stay outside) - note: I call this guy the Outside boss.
2-5 stay low but not too low (an enemy ship thing comes from bottom of screen, middle). When boss teleports, go up or down. He'll be dead quickly anyway.
2-6 easy stage but very dangerous boss (I call him Wide Boss). Stay in the centre of screen during power-ups part of wave and stay there to destroy boss' two guns ASAP - don't move, don't chase ufos - and then he's helpless.
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3-1 - Be aware of the bullets in the stage (Field cannot stop them). Sub-boss 1 is a danger as is the difficult secton with bigger enemies going upwards. MOON (tuning fork boss) stay low and you'll be safe.
3-2 - Watch for lasers . Watch for 8-sided enemies. Side guns cannot shoot through your circle. Boss stage ('classic' layout with bases) is slightly dangerous. Target sphere at top. Run when his orbitals fly off (they shoot lasers) and when he extends, get under a base. Quickly.
3-3 - after orbiting the huge boss watch out for the Nagoya boss from 2-3 - once properly under the big boss and central, take out four guns and target the central hatch. When it opens the gravity beam pulls you in (but doesn't hurt you). Press down to counter it. This boss is super easy really.
3-4 - stay middle to shoot laser turrets (but then avoid the lasers!), watch out for boss from 2-4 and then navigate the box section (Go up until you can't, go right, go up until you have to go left - do that twice, go up until you go right (to the middle). Outside boss turns up. After him is a quick and tough navigation section, then a grid shows up, move to the BOTTOM MIDDLE immediately! LADYBIRD (stay low, don't move - the boss doesn't shoot).
3-5 - series of easy boss battles with some easily-destroyed box enemies in the background (you can mostly ignore them). Stay bottom middle. After 2-5 boss comes the 2-6 boss (Wide Boss) - get ready be in middle of screen to target his guns immediately. Then go low (to avoid armoured enemies show from 14). MANDALA - go low left (or right) and shoot - target centre of boss.
3-6 - shoot early as ever. UNKNOWN - this boss is a prick. Shoot early box waves. Stay low during phase 2 to see where the lasers will go and then go around and up to target the boss. Stick and move (to low right) on phase 3 - this bit can easily steal a life from you. Go to bottom corner on final phase (where the boss expands).

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4-1 - no real danger in level. CENTIPEDE - go middle of his circle and shoot. dies quick
4-2 - super easy (including the Bases boss which is easier this time). HORNET - target 3D cube enemy but move a bit to avoid the small cubes that fly off of him. After that phase is a grid phase (on higher difficulties this is horrible). STAY COMPLETELY LOW and target him on the grid - no danger if you stay very low during grid.
4-3 - carefully dodge between big UFOs. Afterwards watch out for shielded enemies (stay low). PROGRESSIVE UFO: bastard! Stay low whilst his component parts move around. Target them! Afterwards he shoots upwards. Stay roughly level with one side of his central gun to avoid the lines that shoot down. Keep shooting (never stop anyway) to target the boss as he passes. Then when shoots up again, be in same place but move maybe 3-4 ships up from bottom (to avoid the lines crossing over). Practice this stage, it happens again later in the game (I call him Lines boss).
4-4 - starts with a tough boss rush - practice this stage. OCTOPUS - he doesn't shoot but after he grabs you (stay still and shoot for max damage) and releases you, watch out. He'll fly about a bit. Don't stay too near any edge of the screen.
4-5 - really easy with weak versions of early bosses. BUTTERFLY no danger on easy - target white spots. The outline of the 'wings' can be safely flown over as well.
4-6 - AXON is a bastard if you don't learn his attacks. He shoots out paddle things that kill you very quickly - stay middle bottom to avoid first paddle - and then move a little left to avoid the diagonal paddles as they come out. Then target the centre.

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5-1 - WATER STRIDER. Stay low right to avoid him completely. Takes seven minutes (thanks Myupyon, this helped big time!).
5-2 - pretty easy apart from a skyscraper bit (towers in the background can destroy you) with the boss the boss from 2-4. CRAB - tough boss - stay out of range - watch out for the projectiles (easy to avoid and you can shoot them when they float). Go across the screen when the boss jumps, don't take risks - this takes a while but is worth being patient on.
5-3 - ULTIMATE UFO - super easy apart from a reappearance from the Lines boss.
5-4 - you can leave the road/path (those lines can't be crashed into) so dont let the big frog thing thing sit on you! SQUID - pretty easy - during projectiles part, stay low middle until you have to move and then circle upwards to get near to the boss.
5-5 - another boss rush including the Line boss, you should be well-versed on how to beat him now. VERTEBRATE - no bullets to worry about - just watch the patterns and get ready to navigate through this easy boss.
5-6 - if you stay perfectly central you'll fly safely to the boss. If you died on the last level though, get some power-ups. NAMELESS - completely owned by the Field weapon. You won't die.
0 - shoot the invader.

After the credits and score screens you'll get the achievement.

here's a complete video from "Garth Brown" aka APCGrayLocked.

He mentions TA in the description so i think he should be cool with the video getting posted here.