Oh my god, it's been nearly a month and there still hasn't been a review, so I'm going to do one now.
Level design: 7.8/10
To be honest, this is actually a good level. In fact, this is one example that takes the concept of nonlinearity and throws it on its head, and this has been executed quite well in the form that it revolves around the concept where the player is given a choice of doors to go through, and it's a very novel concept that has been put to incredibly great use as it can affect the overall outcome of the level, although not in a large way, and it encourages replay value. The changes in presentation to objects as you approach them is awesome as well, especially the falling blocks as you step on them, which I liked, and the landforms are not too flat and barren and have a lot of variety to them. However, what I liked the best about this level is the fact that every section has at least something unique about it, which is usually retained largely for that section, such as spinjumping over Thwomps, solving a simple switch puzzle or detonating a skull switch and going back to see if something has changed. Unfortunately, I found a very glaring fault with the level, should the player choose to do this:
Yep, you know what this is - if you throw the springboard up onto the ledge above, it's impossible to get back because the platforms leading up to it have sunk, so the player has to commit suicide. But design-wise, that's the only real flaw with the level design, and it's still good even after reviewing it.
Graphics and music: 7.92/10
You did a good job with the music choice. It captures the feeling of adventuring in a lost pyramid very well, but what I didn't like was the sudden change to the standard SMB3 underground theme in the boss chamber, because it destroys the foreboding sense as the player is ready to take on the boss. You could keep using the level's music in that section but that requires Lua; alternatively you could go for no music at all. In terms of the graphics, they go very well with the music track used, and there are no clashes or cut-offs, while the level doesn't appear too barren. Also, some of the enemies are tailored to fit in with the theme of the level, such as the mummified Hammer Bros. and sand Thwomps, which is awesome to see - it's a shame not all of the enemies are mummified or sand-themed though, and the Thwomp has a problem with it which I'll elaborate on shortly. The decorations used are very repetitive as it's just pillars and wall-mounted torches, and thus some ceiling decorations would be welcome in this level.
NPC placement: 6.8/10
A trend that I've seen throughout all the levels I've reviewed is that the other aspects are good, but the NPC placement suffers in comparison. This level is no exception, but it doesn't suffer as much, so don't worry. First of all I'm going to address an issue I flagged out just a little whole ago and that's the Thwomps. Because they blend in with the surroundings, it's very hard to spot the Thwomp until it's crashing down (it's an SMB3 Thwomp), and thus it's very easy to get damaged. Replacing the SMW Thwomp would be a good idea to prevent this. This does not also go with the fact that the NPC placement is rather sporadic. Even the first section in itself is quite spammy with enemies, and this is quite common throughout the level. However, this is balanced by the number of powerups that are in the level, but this also is influenced by what path the player takes. The Moon Coins are also a good idea to encourage replay value, but there are only 3 instead of the expected 5, so increasing the score each coin gives would be a good idea. There is one more issue in this level that I have not addressed yet, and that is the boss fight. Through rather awesome design and nonlinearity, one would expect an epic boss fight, but that is not true. The Rinkas are a neat addition but other than that the boss is a rather easy kill, considering that the vegetables constantly spawn and they can hit the boss about three times before dropping away.
Overall result: 7.5/10
First and foremost, fix that springboard flaw because it's a level-breaker, and possibly reduce the number of enemies with it as well. But other than that, it's still a great level, I need to give you that.