Thanks for letting me know, I'll fix those up. But the materia not appearing is strange. I remember changing the location it spawns from (so that it appears from Keeper's new location) and testing it a few times. I'll need to look at it again; and it now drops a HP<->MP Materia instead, I moved Mega All to the purple Materia cave in it's place.
EDIT: I had a look at the flevel and tested it out in-game, the Materia drops when Keeper dies but it can't be seen. It can be picked up however, search around where Keeper was standing before. I'll try and make it visible for the next update patch.
I moved the key to the basement to a treasure chest (where the Enemy Launcher was) while the Enemy Launcher itself is in the other wing of the Shinra Mansion (replacing a Magic Source). The reason being that Lambda is a strange fight and I didn't want to prevent access to Vincent, but I wanted to make Odin tricky to obtain. Basically, he'll transform when he's attacked while a variable is sitting on a certain value. It starts at 0, and whenever you hit him, it adds 6 to this value. When he uses 13th Aura, it adds 13 to the value. You're looking to make a prime number with the clue being: 34 come before it, and you have to go one over his. But I've been thinking that it's not a good fit for this kind of mod though; I might change it back to the standard fight and use this Lambda build for another project depending on how people find it.
The mod is quite easy but glad you're enjoying it all the same, the basic idea was to just make it fun to play; sometimes it's nice to just cut loose instead of getting knocked about all the time.