SuperTux

Apart from making just rom hacks, I have also worked quite a bit with other games. I've either modified them, or made them new levels.

SuperTux is one game I have spend a lot of time with. Before I did much rom hacking, I used to make levels for SuperTux MileStone 1 (v. 0.1.3), and managed to come up with an actual series called Adventure to the new World (ATTNW for short). It's formed of three separate parts in such way that parts 2 and 3 follow the first one.

After ATTNW series was done, I used to create two separate levels, I wanna be the SuperTux (IWBTST) 1 and 2 for SuperTux 0.3.1 which would be a beta release of SuperTux Milestone 2. I haven't checked, but they might be compatible with the actual Milestone 2 as well.

Yet after IWBTST, I returned making levels for Milestone 1. I ended up finishing a world map which I named Bonus Island X. After Bonus Island X, I started working on yet another levelset which I think was supposed to be yet another part for ATTNW, but ended up being discontinued. This one got quite large though, and has 24 playable levels in total. It's called Tux New Journey, and I personally think it's the most polished of all these levelsets.

So yeah.. quite many levelsets to be downloadable here if you like :D

Mandatory expansions ⚠

Playing my levelsets for Milestone 1 requires some expansions to original SuperTux 0.1.3. In particular, you'll need to download the following two zip files:

Christoph's Forest 2 contains forest world tilesets and background images for SuperTux Milestone 1. The latter one has additional music tracks and even more background images to use. Most of them are from the above-mentioned mod, but there are also some FFVII midi files there.

Put the files in appropriate subfolders under your SuperTux/data/ directory. Music tracks should be put in /data/music, and background images, and tilesets in /data/images/background, and /data/images/tilesets respectively.

Levelsets

Each one of these levelsets contains a ReadMe as an installation guide. Make sure to read the ReadMe in order to install the levelsets properly.
Remember to also install the mandatory expansions beforehand!

I have licensed my SuperTux levelsets under CC-BY-SA 4.0. You are thus free to redistribute, edit, or for example port the levelsets over for recent SuperTux releases. If you happen to do so though, credit me as the original author of the levels, and remember that I don't personally own the mandatory expansions required for playing my levelsets.

Click name for information
Adventure to the new World (0.1.3) Download
First part of the ATTNW series.
Adventure to the new World 2 (0.1.3) Download
Second part of the ATTNW series.

Around a half of the levels are such that I used to create with a friend of mine in the mid 2000s when we were young, and didn't know much about game development to say the least. The levelset gets a bit better starting at level 10 or so though.
Adventure to the new World 3 (0.1.3) Download
Last part of the ATTNW series.
Bonus Island X (0.1.3) Download
A new bonus island by self-made levels.

There are different kinds of paths to choose consisting of 2 or 3 levels each. Once you beat all the levels in one path, you can access another part of the worldmap with more paths to access. Ultimately, a certain path leads to the final dungeon of this bonus island.
Tux New Journey (0.1.3) Download
My newest SuperTux levelset which I unfortunately ended up never finishing.

I don't remember clearly, but I think this one was supposed to become ATTNW 4, but I'm not sure about that. Nevertheless, I think these levels are great (even though I made them :D), and you should definitely try them out. Playing the levels works the best via the built-in level editor.
I wanna be the SuperTux (0.3.1) Download
A large level for SuperTux 0.3.1. Might work with Milestone 2 as well.
I wanna be the SuperTux 2 (0.3.1) Download
Yet another large level for SuperTux 0.3.1. Might work with Milestone 2 as well.

I think this one is better than I wanna be the SuperTux in overall, but there is this one room which is very stupidly implemented. Check the ReadMe for details, so that you won't get stuck there if you want to play this level.