Overview:
- Estimated achievement difficulty: 7/10
- Offline: 9/12 (155 )
- Online: 3/12 (45 )
- Approximate amount of time needed to 200 : 5+ hours
- Minimum number of playthroughs needed: 2
- Number of missable achievements: None
- Number of glitched achievements: 2
- Do cheat codes disable achievements: No cheats
- Does difficulty effect achievements: Yes

Introduction:
Welcome to 0 Attack Day on Earth. This game is like the love child of Contra, Megaman and R-TYPE. There is A LOT happening on the screen all at once, always. During the times when you have a somewhat clear screen, your biggest challenge will be crashing into an enemy that has just come out of nowhere.

The game has two glitched achievements, Crucible and Onslaught, but they are glitched in your favor. Although the achievement description requires you to clear the game on the required difficulty, the game actually only requires that you clear the final stage. So make your first playthorugh on easy, then replay the final stage on hard. You will have to beat the entire campaign on at least normal in one sitting without dying for a different achievement so, while possible to simply reload the last chapter on normal for Crucible, it should unlock on your way to Gold Hammer.

The online co op has very bad connection issues that create severe lag. Since there is no local co-op, this makes things all the more frustrating. On top of that this is a very unpopular title from the arcade, which can make matchmaking very slow. I would strongly recommend using the achievement trading thread HERE to find a partner to work with.

Step 1 – Single player:
Start off by playing through the game on easy. You should use this opportunity to get a feel for the game and test different strategies and see which ships that are most effective for you. Once you have completed the game, reload the final stage on hard for Onslaught. If by some chance you did not unlock the three kill achievements during your first run, simply replay the required level to get the desired kill.

Next will be the most frustrating conquest you have attempted in a long time, you will need to playthrough the entire game again, in one sitting from start to finish on at least normal difficulty, without losing a single life to unlock Gold Hammer. Crucible will unlock at the same time if you didn't already reload the last chapter to unlock it that way. The only advice I can give you is to make good use of the bombs by only using them when there are lots of enemies surrounding you. They will refill after each stage. Even though there is a time limit, take your time and try not to rush, otherwise you will find yourself boosting across the screen and flying straight into a purple cloud. See the achievement guide for more information.

The only remaining single player achievements you should now need are the two for being shot down 256 times and gaining all ranks. A very good strategy to get these both done at once is to play the final boss on hard, lose all three lives and then finish him off. You may even get to the final rank of first lady before being shot down 256 times.

Step 2-Multi-player:
The three multi player achievements are actually very simple and easy to obtain, but the bad lag and the fact that not many people play this game make them difficult.

Simply host or join a co op match and you will automatically unlock one achievement. Next, host or join a control point game and occupy all control points to unlock another achievement. For your final achievement, kill 100 targets in co-op mode. Green targets do not count toward the achievement - orange targets are the only ones that count. This is easier said than done as the kill is only awarded to the player who delivered the final shot. This is best done boosting with a friend taking it in turns to host and farm the orange targets.

Conclusion:
CONGRATULATIONS! You should now have 200 and can add another arcade title to your 100% list.