Now to answer some questions about Raiden IV:
25. Mission 7 [Destroy Protection Unit] (20G)
LEVEL7を敵破壊率100％でクリア（Xbox 360 MODE・SCORE ATTACK MODE.・難易度EASY以上）
*100% clear on enemy destruction rate in Level 7
You may have noticed that no matter how you seemingly destroyed every last enemy in Level 7, you can't get the achievement right? A 99.7% rate. Well, the last 0.3% is actually the Sol in this level. Destroy it too to get the achievement.
Free Play:
Every time you complete a stage and move onto the other in Xbox 360 mode, you gain a credit to use. After reaching Level 2-7 and fighting the final boss, Free Play will be unlocked, both for Arcade and Xbox 360 modes.
Weapon specialization achievements:
One of those "you-screw-up-and-have-to-replay-from-1st stage-all-over-again" achievements. Besides the usual strategy of collecting the desired weapon orbs carefully, make sure to mostly die at the right when you lose a life, as the ship respawns on the left, which may accidentally take any weapon you don't wish to. If you lose a continue, you will notice that the ship starts with the Vulcan weapon, if you are doing a weapon achievement other than the Vulcan. Not to worry, you can shoot, make sure to take the 1st weapon orb after losing a continue you want for the weapon achievement to continue on.
37. Boss Rush Mode Clear (30G)
「BOSS RUSH MODE」をクリア（コンティニュー可・難易度NORMAL以上）
*Continues allowed; Normal difficulty and above
The official Raiden IV blog has made a clarification with this achievement; Boss Rush mode no longer allows continues. This makes attaining it harder. Link:
http://raiden4.air-nifty.com/blog/2008/10/74-9564.html
26. Comprehensive Mission [Destroy Sol] (30G)
全てのソルを破壊（Xbox 360 MODE・SCORE ATTACK MODE.・難易度EASY以上）
*All Sols destroyed
Sol Locations:
Level 1: Near the second tank that spreads bullets in a circle, diagonally left of the position where the fairy is just before you fight the boss.
Level 2: Just before the 2nd long bridge that stretches across the screen, on the left.
Level 3: Same as Arcade;
http://raiden.mossjp.co.jp/raiden4/arca ... ure_d.html
Level 4: Same as Arcade;
http://raiden.mossjp.co.jp/raiden4/arca ... ure_d.html
Level 5: After reaching the giant planetoid, look out for when the screen moves horizontally right and then vertically anti-clockwise. You will spot a Sol on the right as it changes from horizontal to vertical.
Level 6: At the entrance of the satellite platform.
Level 7: At the entrance of the giant spaceship, right after destroying the giant white stealth bomber.
31. Double Play [First Checkpoint Breakthrough] (10G)
ダブルプレイでLEVEL1をクリア（Xbox 360 MODE・難易度NORMAL以上）
*Clear Level 1 in Double Play
32. Double Play [One in Body and Mind] (30G)
ダブルプレイでLEVEL3をクリア（Xbox 360 MODE・難易度NORMAL以上）
*Clear Level 3 in Double Play
33. Double Play [Full Proficiency] (50G)
ダブルプレイで1周目をクリア（Xbox 360 MODE・難易度NORMAL以上）
*Clear 1st Round in Double Play
There's seemingly no continues if both of your ships die in Double mode. Achievements 32-33 requires you to play through from Level 1-1 to 1-7 in order to get these two. All I can say is: you need a lot of practice.
Plus secret achievements revealed:
39. Blue Flash (20G)
ダブルプレイで1P機で一切ショット・ボムを打たず、
2P機の攻撃のみで1ステージをクリア
（Xbox 360 MODE・難易度NORMAL以上）
*In Double Play, clear a stage using 2P for shooting and bombing, do not use 1P; Xbox 360 mode, Normal difficulty and above
40. Nice Bomb (5G)
ボムで敵キャラを12体以上同時に破壊（全ゲームモード、難易度不問・DUAL不可）
*Destroy 12 enemies with 1 bomb, all game modes and difficulties allowed, Dual not allowed
41. Undaunted Fighting Spirit (15G)
残機0、残ボム0でいずれかのLEVELをクリア（全ゲームモード、難易度不問・DUAL不可）
*Clear a level with no bombs and lives, all game modes and difficulties allowed, Dual not allowed
42. Big Fireworks Festival (15G)
ボムを7つストックして全て使い尽くす（全ゲームモード、難易度不問・DUAL不可）
*Use up all 7 bombs at once, all game modes and difficulties allowed, Dual not allowed
43. Sticky Victory (15G)
ボスをタイムアップで自爆させる （全ゲームモード、難易度不問・DUAL不可）
*Let a boss die from time out, all game modes and difficulties allowed, Dual not allowed
44. Miclus (30G)
?????
(At this point in time, no one has yet to attain this achievement, help is needed to find all Miclus locations.)
