Hello @sonic2kk, these look like some lines of interest from your log:
[00000130:] EXCEPTION handling: System.NotImplementedException: The method or operation is not implemented.
"<unnamed thread>" tid=00000130 this=06770120 , thread handle : 03467af0, state : not waiting
at System.Runtime.InteropServices.Marshal.ThrowExceptionForHR (int) [0x0000a] in <e70d6e9587d64cb3abb4b3f99bbf5a0d>:0
at (wrapper cominterop) System.Windows.Forms.UnsafeNativeMethods/IPersistStreamInit.Load (System.Windows.Forms.UnsafeNativeMethods/IStream) [0x0001b] in <5733f93bb22240d29f87471942e9a982>:0
at (wrapper cominterop-invoke) System.Windows.Forms.UnsafeNativeMethods/IPersistStreamInit.Load (System.Windows.Forms.UnsafeNativeMethods/IStream) [0x00000] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.AxHost.DepersistFromIStreamInit (System.Windows.Forms.UnsafeNativeMethods/IStream) [0x00008] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.AxHost.DepersistControl () [0x001c5] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.AxHost.SlowActivate () [0x0002c] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.AxHost.ActivateAxControl () [0x00017] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.AxHost.TransitionUpTo (int) [0x00083] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.AxHost.CreateHandle () [0x00012] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Control.CreateControl (bool) [0x00045] in <5733f93bb22240d29f87471942e9a982>:0
at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control.CreateControl (bool) [0x00032] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Control.CreateControl (bool) [0x000b3] in <5733f93bb22240d29f87471942e9a982>:0
at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control.CreateControl (bool) [0x00032] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.AxHost.EndInit () [0x00015] in <5733f93bb22240d29f87471942e9a982>:0
at _21_Jogo_BETA.Softwaves.InitializeComponent () [0x0086f] in <5e4219adff1b4af99ee293bb40722ee2>:0
at (wrapper remoting-invoke-with-check) _21_Jogo_BETA.Softwaves.InitializeComponent () [0x00031] in <5e4219adff1b4af99ee293bb40722ee2>:0
at _21_Jogo_BETA.Softwaves..ctor () [0x00022] in <5e4219adff1b4af99ee293bb40722ee2>:0
at (wrapper runtime-invoke) object.runtime_invoke_void__this__ (object,intptr,intptr,intptr) [0x00027] in <e70d6e9587d64cb3abb4b3f99bbf5a0d>:0
at <unknown> <0xffffffff>
at (wrapper managed-to-native) System.Reflection.RuntimeConstructorInfo.InternalInvoke (System.Reflection.RuntimeConstructorInfo,object,object[],System.Exception&) <0x00012>
at System.Reflection.RuntimeConstructorInfo.InternalInvoke (object,object[],bool) [0x00005] in <e70d6e9587d64cb3abb4b3f99bbf5a0d>:0
at System.RuntimeType.CreateInstanceMono (bool,bool) [0x00095] in <e70d6e9587d64cb3abb4b3f99bbf5a0d>:0
at System.RuntimeType.CreateInstanceSlow (bool,bool,bool,bool) [0x00009] in <e70d6e9587d64cb3abb4b3f99bbf5a0d>:0
at System.RuntimeType.CreateInstanceDefaultCtor (bool,bool,bool,bool,System.Threading.StackCrawlMark&) [0x00027] in <e70d6e9587d64cb3abb4b3f99bbf5a0d>:0
at System.Activator.CreateInstance<T_REF> () [0x00015] in <e70d6e9587d64cb3abb4b3f99bbf5a0d>:0
at _21_Jogo_BETA.My.MyProject/MyForms.Create__Instance__<T_REF> (T_REF) [0x0008d] in <5e4219adff1b4af99ee293bb40722ee2>:0
at _21_Jogo_BETA.My.MyProject/MyForms.get_Softwaves () [0x00000] in <5e4219adff1b4af99ee293bb40722ee2>:0
at _21_Jogo_BETA.Start.Start_Load (object,System.EventArgs) [0x00063] in <5e4219adff1b4af99ee293bb40722ee2>:0
at (wrapper delegate-invoke) <Module>.invoke_void_object_EventArgs (object,System.EventArgs) [0x00071] in <e70d6e9587d64cb3abb4b3f99bbf5a0d>:0
at System.Windows.Forms.Form.OnLoad (System.EventArgs) [0x000d1] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Form.OnCreateControl () [0x00031] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Control.CreateControl (bool) [0x000ed] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Control.CreateControl () [0x00008] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Control.WmShowWindow (System.Windows.Forms.Message&) [0x00051] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Control.WndProc (System.Windows.Forms.Message&) [0x0071b] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.ScrollableControl.WndProc (System.Windows.Forms.Message&) [0x00043] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.ContainerControl.WndProc (System.Windows.Forms.Message&) [0x0001a] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Form.WmShowWindow (System.Windows.Forms.Message&) [0x00013] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Form.WndProc (System.Windows.Forms.Message&) [0x00290] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Control/ControlNativeWindow.OnMessage (System.Windows.Forms.Message&) [0x00001] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Control/ControlNativeWindow.WndProc (System.Windows.Forms.Message&) [0x000b3] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.NativeWindow.Callback (System.Windows.Forms.Message&) [0x00025] in <5733f93bb22240d29f87471942e9a982>:0
at (wrapper remoting-invoke-with-check) System.Windows.Forms.NativeWindow.Callback (System.Windows.Forms.Message&) [0x00032] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.NativeWindowProc.Callback (intptr,int,intptr,intptr) [0x00037] in <5733f93bb22240d29f87471942e9a982>:0
at (wrapper native-to-managed) System.Windows.Forms.NativeWindowProc.Callback (intptr,int,intptr,intptr) <0x00067>
at <unknown> <0xffffffff>
at (wrapper managed-to-native) System.Windows.Forms.SafeNativeMethods.ShowWindow (System.Runtime.InteropServices.HandleRef,int) <0x00012>
at System.Windows.Forms.Control.SetVisibleCore (bool) [0x00061] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Form.SetVisibleCore (bool) [0x000d1] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Control.set_Visible (bool) [0x00001] in <5733f93bb22240d29f87471942e9a982>:0
at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control.set_Visible (bool) [0x00032] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Application/ThreadContext.RunMessageLoopInner (int,System.Windows.Forms.ApplicationContext) [0x000cb] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Application/ThreadContext.RunMessageLoop (int,System.Windows.Forms.ApplicationContext) [0x0001a] in <5733f93bb22240d29f87471942e9a982>:0
at (wrapper remoting-invoke-with-check) System.Windows.Forms.Application/ThreadContext.RunMessageLoop (int,System.Windows.Forms.ApplicationContext) [0x00033] in <5733f93bb22240d29f87471942e9a982>:0
at System.Windows.Forms.Application.Run (System.Windows.Forms.ApplicationContext) [0x00006] in <5733f93bb22240d29f87471942e9a982>:0
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun () [0x00044] in <c45854c8c8084c208e5c27fc30fedab6>:0
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel () [0x00035] in <c45854c8c8084c208e5c27fc30fedab6>:0
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run (string[]) [0x0001b] in <c45854c8c8084c208e5c27fc30fedab6>:0
at _21_Jogo_BETA.My.MyApplication.Main (string[]) [0x00017] in <5e4219adff1b4af99ee293bb40722ee2>:0
at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) [0x00027] in <5e4219adff1b4af99ee293bb40722ee2>:0
Appears to still be an issue with Proton 9.0-1 and Proton Experimental (20240522).
Log from an execution with Proton Experimental: steam-938520.log
proton 9.0-1x1 2024-06proton experimentalx1 2024-06
Compatibility Report
System Information
I confirm:
Symptoms
Launching the game shows what seems to be a .NET related error:

Reproduction
Launching the game with Proton is all that seems to be needed to reproduce the issue.
Proton Log: steam-938520.log