Need some advice on my game music (take 2)

My first impression is that these instrument samples are rather poor, or poorly used. Sounds like really low-budget SNES. Find a way to get better and warmer instruments. I really think that needs to be addressed before I can fairly judge any other aspects of the composition.

P.S. My friends and I were playing Second Reality Project late last year and it had some cool stuff.

Additional Spam:
I just finished listening to the entire soundtrack. Here's a few thoughts on some of the more notable and more nefarious tracks:

Inside Castle Walls
Very good instrument usage and nice melody. It succeeds in being reminiscent of the Yoshi's Island castle music, and the orchestral hits are used in a Mario 64-esqe manner.

Ending Part #1
My favorite part is the instrument that starts off as the melody/harmony in the beginning. I also really like the use of the bongos. The lead instruments tend to warble too much on this track, but otherwise I think it's solid.

Boss Battle
Instruments are generally well used here. Sometimes the melody hits some off-sounding notes. Also it sometimes gets too soft for a Boss track, even if those parts are good.

The Good, The Bad, & The Spy
The percussion has a good rhythm and it changes up half-way through to stop from getting stale. The harmony from the glockenspiel or whatever it is works well.

Thirdspace
Has some cool instrument usage, but I think the main instrument is out of place. Also, I think you may want to check to ensure everything is in tune.

Mario's Athletics
I like the Mario 3 homage at the beginning. The song is pretty upbeat, but it could go "higher" if you know what I mean. Also, I think the constant percussion is wrong for the song. It needs to mix up more; stop and go, etc.

Bowser's Starship
The intro is all right. Then the lead instrument comes in with a really annoying tone. It's also too giddy sounding for the final stage. That electric guitar sample you're using as the harmony in some places just sounds wrong. Maybe it's just off-tune, but I don't think that instrument works well in this spot at all.

Meridian Assault
If you're going to make a blatant "Meridian Worship" reference, you might as well just include that song in its original form. Meridian Assault is a neutered stump in comparison to Kikuta's gem.

It sounds like you're using Super Mario World's instrument bank, so there may be a limitation preventing you from using new instruments. In that case, you need to be very careful about choosing instruments. You need to make sure the instruments mesh with each other to form a cohesive mood. Make sure your harmonic and percussive instruments play into your lead instrument(s).

A lot of the music in this soundtrack sounds drab, repetitive, and monotone. You need more dynamics in general. More volume changes, more tempo changes, more pitch changes. Also, make sure you're not hitting the wrong notes at the wrong time. I'm not expecting you to be Koji Kondo, but you should look at his music to see what you're doing wrong, and improve upon that.

Jam it back in, in the dark.