Perfect example of a great underdog of the week
With some work these games have the potential to get some high rankings in the flash portal. I am by no means a flash artist but it is obvious to me that in these beta games you have clear talent. With that being said, here's what I think you can do to make these high-ranking games.
I know you said you don't want to force music tastes on us but music is a key part of your flash animations. It can set the tone for any one of the games. In your Zelda style game for example, music could tell us whether its a creepy dungeon, and uptempo cave, or just someplace bright. Music can compansate for average graphics because music can tell a story and setting as well. If you can't make your own music and you don't want to use pop culture songs, go to the audio portal and look at some of the artists that work predominantly in the video game section. TritoneAngel, Paragon x9 and Stage 3-1 are artists I can think of off the top of my head that might have good stuff for you to work with.
You don't need 3D graphics or fancy looking characters. If shapes are your style then stick with them, just make them sharper and add a wider variety of colors. Look at a game called Trapped 4 on this site. It only uses shapes, but it has sharp, bright graphics, and in my opinion, that's all it needs. Take that into consideration as well when you expand these games.
Personally, I love the platformer idea and you don't need a boss but if you can implement it, then by all means do it.
The Zelda style game can also turn out to be really top-notch stuff if you add enemies and more defined graphics.
The shooter is addictive. Very addictive. With music, power ups and more aggressive enemies, this flash alone would give more more reason not to do homework that night.
The mouse game thing is always intriguing but I've seen it done a hundred times already. Work extra hard on that to make it really unique so it stands out from the rest.
Oh, and dont mistake my tone for being mean towards your flash, I love your stuff and you have great ideas. I'm only being very picky in this review because I know you have talent and that with more work you could really make a mark in newgrounds. I also noticed that in the other reviews people have given you, you have responded and you seem to be taking in the feedback people give you. I look forward to your next completed project.