Achievements in Raiden IV revealed! By 5pb's Sakari Masaki's blog:
http://hgqp.blog44.fc2.com/
1. Level 1-1 Boss Shot Down (10G)
LEVEL1-1ボス「エグゼレイ・イス」撃破(Xbox 360 MODE・難易度NORMAL以上)
2. Level 1-2 Boss Shot Down (10G)
LEVEL1-2ボス「オルド/フュラス/マイラザード」撃破(Xbox 360 MODE・難易度NORMAL以上)
3. Level 1-3 Boss Shot Down (10G)
LEVEL1-3ボス「ファメル・ヤー」撃破(Xbox 360 MODE・難易度NORMAL以上)
4. Level 1-4 Boss Shot Down (15G)
LEVEL1-4ボス「アグェン/エウァト」撃破(Xbox 360 MODE・難易度NORMAL以上)
5. Level 1-5 Boss Shot Down (15G)
LEVEL1-5ボス「ダ・ルチュラ」撃破(Xbox 360 MODE・難易度NORMAL以上)
6. Level 1-6 Boss Shot Down (15G)
LEVEL1-6ボス「イスドガーラム」撃破(Xbox 360 MODE・難易度NORMAL以上)
7. Level 1-7 Boss Shot Down (15G)
LEVEL1-7ボス「ホルダ・ガーディア」撃破(Xbox 360 MODE・難易度NORMAL以上)
8. Level 2-1 Boss Shot Down (20G)
LEVEL2-1ボス「エグゼレイ・イス」(2周目)を撃破(Xbox 360 MODE・難易度NORMAL以上)
9. Level 2-2 Boss Shot Down (20G)
LEVEL2-2ボス「オルド/フュラス/マイラザード」(2周目)を撃破(Xbox 360 MODE・難易度NORMAL以上)
10. Level 2-3 Boss Shot Down (20G)
LEVEL2-3ボス「ファメル・ヤー」(2周目)を撃破(Xbox 360 MODE・難易度NORMAL以上)
11. Level 2-4 Boss Shot Down (25G)
LEVEL2-4ボス「アグェン/エウァト」(2周目)を撃破(Xbox 360 MODE・難易度NORMAL以上)
12. Level 2-5 Boss Shot Down (25G)
LEVEL2-5ボス「ダ・ルチュラ」(2周目)を撃破(Xbox 360 MODE・難易度NORMAL以上)
13. Level 2-6 Boss Shot Down (25G)
LEVEL2-6ボス「イスドガーラム」(2周目)を撃破(Xbox 360 MODE・難易度NORMAL以上)
14. Level 2-7 Boss Shot Down (30G)
LEVEL2-7真ボス「ホルダ・ゲシュトルアダ」を撃破(Xbox 360 MODE・難易度NORMAL以上)
15. Title [Ace] Acquired (35G)
難易度NORMALを1クレジットでクリア(Xbox 360 MODE)
*1 credit clear on Xbox 360 mode Normal difficulty
16. Title [Hero] Acquired (40G)
難易度HARDを1クレジットでクリア(Xbox 360 MODE)
*1 credit clear on Xbox 360 mode Hard difficulty
17. Title [Legend] Acquired (45G)
難易度VERY HARDを1クレジットでクリア(Xbox 360 MODE)
*1 credit clear on Xbox 360 mode Very Hard difficulty
18. Title [Incredible] Acquired (50G)
難易度ULTIMATEを1クレジットでクリア(Xbox 360 MODE)
*1 credit clear on Xbox 360 mode Ultimate difficulty
19. Mission 1 [Fairy Rescue] (5G)
フェアリーを救出完了(Xbox 360 MODE・SCORE ATTACK MODE.・難易度EASY以上)
20. Mission 2 [Preemptive Attack] (10G)
LEVEL.2をフラッシュショット率4.25以上でクリア(Xbox 360 MODE・SCORE ATTACK MODE.・難易度EASY以上)
*Level 2 Clear with Flash Shot rate of 4.25 and above
21. Mission 3 [Destroy Jeep] (10G)
ミッション3「ジープ破壊」:10G
ジープを破壊(Xbox 360 MODE・SCORE ATTACK MODE.・難易度EASY以上)
22. Mission 4 [1UP Acquisition] (10G)
1UPアイテムを獲得(Xbox 360 MODE・SCORE ATTACK MODE.・難易度EASY以上)
*1UP item acquired
23. Mission 5 [Destroy Tank Regiment] (10G)
LEVEL5の敵戦車部隊を全て破壊(Xbox 360 MODE・SCORE ATTACK MODE.・難易度EASY以上)
*Destroy entire tank regiment in Level 5
24. Mission 6 [Enemy Fleet Annihilation] (15G)
LEVEL6にて敵宇宙艦隊を全て破壊(Xbox 360 MODE・SCORE ATTACK MODE.・難易度EASY以上)
*Destroy entire enemy fleet in Level 6
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
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
27. Vulcan Fighter (30G)
バルカンのみで1周目をクリア(Xbox 360 MODE・コンティニュー可・難易度EASY以上)
*Clear 1st Round using Vulcan only, Continues allowed
28. Laser Specialist (30G)
LEVEL1でレーザーを取得し、レーザーのみで1周目をクリア(Xbox 360 MODE・コンティニュー可・難易度EASY以上)
*Acquire Laser in Level 1, clear 1st Round using Laser Only, Continues allowed
29. Plasma Craftsman (30G)
LEVEL1でプラズマを取得し、プラズマレーザーのみで1周目をクリア(Xbox 360 MODE・コンティニュー可・難易度EASY以上)
*Acquire Plasma in Level 1, clear 1st Round using Plasma Laser only, Continues allowed
30. Magician of Proton (30G)
LEVEL1でプロトンを取得し、プロトンレーザーのみで1周目をクリア(Xbox 360 MODE・コンティニュー可・難易度EASY以上)
*Acquire Proton in Level 1, clear 1st Round using Proton Laser only, Continues allowed
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
34. Arcade "Light" Clear (30G)
「ARCADE MODE」<LIGHT>をクリア(コンティニュー可・難易度NORMAL以上)
*Clear Light difficulty in Arcade Mode, Continues allowed
35. Arcade "Original" 1st Round Clear (35G)
「ARCADE MODE」<ORIGINAL>1周目をクリア(コンティニュー可・難易度NORMAL以上)
*Clear Original difficulty (1st Round) in Arcade Mode, Continues allowed
36. Arcade "Original" 2nd Round Clear (40G)
「ARCADE MODE」<ORIGINAL>2周目をクリア(コンティニュー可・難易度NORMAL以上)
*Clear Original difficulty (2nd Round) in Arcade Mode, Continues allowed
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 not allowed; Normal difficulty and above
38. Gallery Complete (5G)
ギャラリーデータを全て収集
*All Gallery data collected
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.)
45. 5,000,000 Points (5G)
5.000.000点を達成(全ゲームモード、難易度不問)
*All Game Modes, all difficulties allowed
46. 10,000,000 Points (5G)
10.000.000点を達成(全ゲームモード、難易度不問)
*All Game Modes, all difficulties allowed
47. 20,000,000 Points (5G)
20.000.000点を達成(全ゲームモード、難易度不問)
*All Game Modes, all difficulties allowed
Summary:
Achievements 1 - 14: Acquired as you play through Xbox 360 mode and defeat bosses, Normal difficulty and above, Continues should not be a factor.
Achievements 15 - 18: 1 credit clear on 4 difficulties on Xbox 360 mode: Normal, Hard, Very Hard and Ultimate.
Achievements 19 - 26: Clear Score Attack missions and requirements, Easy difficulty and above.
Achievements 27 - 30: Use only 1 type of weapon and clear 1st Round Xbox 360 mode, Easy difficulty and above, Continues allowed.
Achievements 31 - 33: Clear Double Play in Xbox 360 mode, Normal difficulty and above, Continues should not be a factor.
Achievements 34 - 36: Arcade Mode clear in Light and Original (both Rounds), Normal difficulty and above, Continues allowed.
Achievement 37: Boss Rush Mode Clear, Continues allowed, Normal difficulty and above.
Achievements 38 - 44: Miscellaneous, unlocked once you complete a specific objective or requirement.
Achievements 45 - 47: All Game Modes (Arcade, Xbox 360, Boss Rush), all difficulties allowed, I guess it should be culmulative points you earn through games.