If you tried to play Rex Rocket recently, you might have noticed that the game doesn't launch properly: more specifically, while it does launch, the only thing it does is zoom in your screen and stay that way until you force-close it from the Windows taskbar. This guide will explain in detail how to fix this issue!


Small disclaimer: I'm not very familiar with the game itself, as you can guess from my playtime. A friend asked me if I could take a look at the game to try and find a fix for it, which is the only reason why I know about the game.

As it turns out, the problem doesn't come from the game itself, rather its dependencies. Every developer who wants to use Steam must integrate Steamworks into their game for it to work properly. This comes in the form of DLL files, which won't always be the same depending on the game. On Steam, right-click on Rex Rocket, then Manage > Browse Local Files. This will take you to Rex Rocket's game files, which should look like this:



The three underlined lines are the DLL files which are required for the Steamworks integration to work properly. These files are the reason why the game doesn't launch: they may correspond to an older version which no longer works, or maybe one of the 3 files doesn't match the others anymore. Either way, here are two possible solutions to fix the issue.

This is the easy solution: as it turns out, the Linux build of the game works perfectly fine! I tested it on my Steam Deck, and as long as you don't accidentally download the Windows build, the game should work correctly (remember, the Steam Deck allows you to play both Windows and Linux builds, so make sure it downloads the right one). It's possible that the MacOS build works as well, but I have no way to test it.

If you don't have a Linux OS, or really want to play on Windows, the only solution is to replace the three DLL files with up-to-date versions (replacing only one or two will not work). However, always remember that DLL files can be dangerous for your computer, and you absolutely shouldn't download any without verifying the source. This is why I'm going to quickly explain who's behind the files we will be downloading for this solution.

The DLL files aren't directly provided by Valve: while Valve is responsible for Steamworks itself, the files we're looking for are libraries which help bridge the gap between Steamworks and the technology used to create the game. For Rex Rocket, two of these libraries were needed, CSteamworks as well as Steamworks.NET. We're going to download the DLLs directly from the developer who's responsible for both of these libraries, Riley Labrecque. If you want to make sure he's a trust-worthy source, you can check out his GitHub profile[github.com] as well as his website[rileylabrecque.com].

Now that we got this out of the way, there are two ZIPs that we must download from two different GitHub repositories. The first we must download is the latest release from the CSteamworks repo, which can be found here: https://github.com/rlabrecque/CSteamworks/releases/tag/v1.30-1.40

Make sure you download the actual release (CSteamworks-v1.30-1.40.zip), and not the ZIP containing the source code. Extract the ZIP, go to the x86 folder and take the CSteamworks.dll file (we won't need the .so file).



The second ZIP we want to download can be found in the latest release for the Steamworks.NET repo. At the time this guide was written, this is the latest release: https://github.com/rlabrecque/Steamworks.NET/releases/tag/2024.8.0

Once again, download the first ZIP, Steamworks.NET-Standalone_2024.8.0.zip, and extract it. The two DLL files we're missing will be found in the Windows-x86 folder. Take these two as well.



Now that you have the three DLL files, use them to replace the old ones in the Rex Rocket folder (once again, to access this folder, right-click on Rex Rocket on Steam, then Manage > Browse Local Files). You should now be able to launch the game!

Important: make sure that you have Steam open when launching the app, as it doesn't seem to be able to get Steam to open on its own, even after applying the fix.

These downloads are 100% safe, but if you don't want to directly download the DLLs anyway, there is a less-convenient alternative, which is downloading a Steam game which has all three files, and transferring them to the Rex Rocket folder. I made a small list of games which have the three DLLs and I tested each of them to make sure Rex Rocket works with them:

• Celeste
  
• Axiom Verge
  
• Salt and Sanctuary
  
• If you don't have any of these, you can use this free game called Interloper

I found these games by looking up games which use the FNA technology, as it is the technology that was used to create Rex Rocket. Keep in mind that a game using the FNA technology doesn't guarantee its Steam version will contain the three DLLs you're looking for.