OK, first of all some basic things:

The first is that you should use the 1.23 JCS instead of the TSF one. If you do, more people can play your levels because not everybody has TSF (=1.24). The second thing is the levelname. Instead of just naming it "jungle", I'd advise you choose a more original name because many levels are named that simple and thus you can easily overwrite a level belonging to an episode, etc. It's the same with readmes, by the way.

Now for the level. It was quiet average.

1. Too less originality. You run around collecting things, kill some enemies and sooner or later find the exit. That's been there thousands of times. Try doing something different, such as a puzzle, a difficult obstacle to cross or whatever comes to your mind.

2. Too easy. In one part there was a dragonfly which was strategically placed and so I got hurt, but in the rest of the level you could easily take your enemies out. Always try giving the enemies some kind of advantage or giving Jazz a disadvantage. For example, flying enemies can get through walls while Jazz can't, so placing them behind walls makes it more challenging.

3. Not all that great eyecandy. It looked decent, but the background was empty for the whole level except at the bottom (fix this by activating 'Limit visible region') and there were a few tilebugs (= tiles that don't fit together). Apart from that it just looks like one of the standard jungle levels, some more creativity in placing eyecandies would be appreciated.

4. Lack of story/plot. A level doesn't neccessarily need one, but it makes everything more fun because the player has a goal, something he needs to achieve. In this level you just run around and kill off enemies until you find the exit.

That was my feedback, think about it.