It would be really helpful if you packaged your levels as a self-contained addon. This way your custom content does not need to be merged with a working data directory which is a real pain for those working on development. Also, it's easier to install your levels since a single file only needs to be placed into the addons folder in the .supertux2 directory (plus it makes it easier for me to make your levels accessible on a larger scale through the in-game addon manager). This can be done by putting all your files into a single .zip file structured as if starting in the supertux/data/ directory. In addition, you need to create a .nfo file so SuperTux can recognize an addon. This is done by creating a text file called something like "lolkat-levels-2.nfo" which contains the something like following text:
- {l Code}: {l Select All Code}
(supertux-addoninfo
(id "lolkat-levels-2")
(version 1)
(type "worldmap")
(title "Lolkat's Levels 2")
(author "Lolkat")
(license "GPL 2+ / CC-by-sa 3.0")
)
This .nfo file along with any directories needed for your addon (levels, music, images, etc.) should then be compressed into a .zip file. You can test if it works by placing it in .supertux2/addons and seeing if you can access/play the levels with the game utilizing the addon menu. These days I do not have the time to set it up myself, so if you can do it then I can make them accessible faster. You can always use any addons downloaded with the game as a guide as to how to set it up.
I wasn't able to play your levels with all the custom content since I was unwilling to modify and track changes in my working tree, but there were a few things I noticed which could improve the set regardless. Most of your levels could benefit from a clear indicator that the level is done, often it seems that they just abruptly stop. You have many lost badguys who fall off the screen before the player can reach them, this makes it impossible for those with obsessive-compulsive disorder to max out the max fragging stat. There are also many minor graphical glitches, often due to tiles being on the wrong layer (I bet this is why Falling Rocks! cannot be completed). This gives many levels an unfinished feel. In addition, you do not use solid tiles very consistently- sometimes they are background and sometimes not, thus it is unclear on initial impression what will interact with Tux. For example, the vertical wood tiles in Hang Tight are a bit confusing since they look the same as the areas Tux can walk, replacing them with poles or the blue wood tiles would make the level more clear (of course when it comes to secret areas feel free to be deceptive). You have a couple of levels that use bicycle platforms which I found to be completely unplayable- these development features should probably be used sparingly and without a ton of other level elements since they still are a bit unruly. I got stuck between the first two houses in Snowbirch, there should be a way out (or a way to suicide) if the trampoline is left in front of the first structure. This level also suffers from inconsistent tile use. The invisible ceiling in Author's Note is obnoxious and should be redesigned. This is a start, as I have yet to evaluate the entire levelset.
I do not mean to be discouraging in any way as most of this is more-or-less polish work. I think these things would really improve your levelset and mean them for constructive purposes. I'd like to post the levels to addons, but it would help if some of the more serious bugs were worked out and they were packaged as an addon.
Keep up the good work, and I look forward to another revision.