Jumping at the corner of blocks above Tux can push him a little to the right saving time. The “displacement” (as OscillatingOcelot calls it) is visually noticeable. Jump at the very back of enemies also saves some time. That’s all I know. OscillatingOcelot is the expert at this kind of stuff.

Yeah, the master-branch on GitHub is always up-to-date (and they were 2103 commits to master since 0.5.1). Though, you can time travel on GitHub if you switch to tag v.0.5.1. Here is the old file: https://github.com/SuperTux/data/blob/1bbcf668304466b37868356e0d0278f2132c90d2/levels/world1/15%20-%20Under%20the%20Ice.stl?short_path=0c79450

However, you can only know for sure if you open the locally saved file on your computer.

To find the second secret you have to jump on the first brick blocks you see in the level and jump up:

Hey everyone, this is my first forum post!

OscillatingOcelot just submitted the first Max% run ever. Respect!

I started this thread because there’s a little mistake in the rules. “Under the Ice” does contain 2 secrets. You can look this up by opening the level stl file in a text editor:

• Linux: /usr/share/games/supertux2/levels/world1/
• Windows: C:\Program Files\SuperTux\data\levels\world1\

However, a much more convenient option is to open the Icy Islands levels in the in-game level editor. This is disabled by default but you can enable it: Set “hide-from-contribs” to “#f” with a text editor. You can find the file in:

• Linux: /usr/share/games/supertux2/levels/world1/info or /home/$USERNAME/.local/share/supertux2/levels/world1/info (I’m not sure which one is right, just try both)
• Windows: C:\Program Files\SuperTux\data\levels\world1\info

Afterwards you should be able to find “Icyislands levels” in the editor.

Furthermore, the Max% category is not really 100%. The game tells you that you completed a level 100% with a blinking level dot. To achieve this you also have to beat the level target time (I recently opened an issue on github concerning this matter https://github.com/SuperTux/supertux/issues/996 What a coincidence!). Though, I would say we should leave it as it is because a real 100% would basically require to beat every level twice.