Blaster Master Zero

***Warning this is missable***
**If you are freaking out thinking you missed something like me, you need both keys as well. The 2nd key will probably be the very last item you collect**
*Complete list of items at the bottom with some possible missing items and locations*

Of course it goes without saying you need to get 100% of the items before beating the game, BUT once you enter the level 7 boss area, you have reached an area of no return. So make sure you get all items before entering the level 7 boss area (the dungeon on the bottom right of the map, you have to reach by foot).

If you also want to get the normal and true ending in one run, instead of 2 playthroughs, you should make a copy of your save in Level 7 before you get all the items. Get the normal ending, load the save up, get 100% of the items, then you can get the true ending.

I pulled the following from a GameFaqs forum post:
- All maps
- All HP upgrades (one for each area, so you should have two health bars once you've got them all)
- All of Jason's sub-weapons (there's 5)
- All of Sophia's main weapons (there's 5 counting the fully upgraded basic attack)
- All of Sophia's sub-weapons (there's 5)
- All of Sophia's maneuvers (there's 4)
***This list is missing the TWO keys you need to progress the game***

You can see this info very easily if you go to the continue game screen from the main menu and click on your save you can see all the info. Sophia and Pilots health. It should be two full health bars.

Little Extra help: Many people are missing 1 HP, searching the internet a lot of people missed the HP in the sewers.

For me I was missing the 4th Manuvor. The boost. It in level 3 top right. You have to go on foot and crawl under the wall to reach the dungeon. I figured I needed a key and would come back later.