This challenge was created with the intention of showing partipicants how easy it is to decompile .NET code,  presented in a fun game challenge. 
The challenge provides a Unity game. This is evident upon launching the game where you're greeted with "Made with Unity".
Exploring the game there's a jump that cannot be made. Rereading the descrption "*Have a look around the map for anything that might be of help. It won't be easy.*" It's evident the challenge is to somehow manipulate the players movement capabilties.![](https://blog.adelaideb9.com/posts/2022/uactf/re-platformer/20220918165442.png)
Investigating the game files and with a quick google search Unity games reveals, the game is most likely built with C#.![](https://blog.adelaideb9.com/posts/2022/uactf/re-platformer/20220918165257.png)
With a tool such as DnSpy it's possible to reverse and modify the C# code.
We need to know figure out where exactly the game code is stored. A quick search for Unity game hacking reveals, it's stored in the Managed folder. Navigating into `RE Platformer_Data\Managed` there's a bunch of DLLs, the game code is contained within `Assembly-CSharp.dll`. ![](https://blog.adelaideb9.com/posts/2022/uactf/re-platformer/20220918170524.png)
Opening this file up in DnSpy reveals `PlayerMovement`, this is exactly what we're looking for.![](https://blog.adelaideb9.com/posts/2022/uactf/re-platformer/20220918170648.png)
To modify the game behaviour, the easiest way to go about it is within the start function. This function is called by the game engine once the object is created.  ![](https://blog.adelaideb9.com/posts/2022/uactf/re-platformer/20220918170757.png)1. Right clicking2. 'Edit Method'3. Modify the gravityScale to say 5% of the original  ![](https://blog.adelaideb9.com/posts/2022/uactf/re-platformer/20220918171341.png)
Then saving the modified file and replacing the orignal one.![](https://blog.adelaideb9.com/posts/2022/uactf/re-platformer/20220918171036.png)
With this we're able to jump our way to the flag.
**Flag**: `UACTF{ALPH4B3T_K1NG_4PPL3}`![](https://blog.adelaideb9.com/posts/2022/uactf/re-platformer/20220918171320.png)