WIN32 SendInput only working for some programs - code included

Question

I started working on a small bot project as a fun way to dive into the win32 api (among other things). In particular, SendInput is only behaving as expected in some instances.

As a proof of concept I set up a loop to send the 's' key just to make sure things are working. If I set the window I want to activate as Notepad, text appears just fine. But if I set the window to Ikaruga, the window pops up but the menu doesn't change (game uses WASD for menu navigation, so it should just continually go down).

I have read in multiple places that games have some (not very reliable) options for blocking external input. To check if that was the case, I found a project where someone built a key sender. The particular project I used is here enter link description here . His code sent 's' keys to Ikaruga as expected.

He included his source code. I've spent a fair bit of time reading over it. While a lot of the functions he is using have been superseded, the overall code flow is similar.

Hopefully, someone can provide me some guidance on what I'm doing wrong.

#ifdef _MSC_VER
#define _CRT_SECURE_NO_WARNINGS
#define _CRT_NONSTDC_NO_DEPRECATE
#endif

#define WINVER 0x0500
#include <windows.h>
#include <stdio.h>
#include <tchar.h>

void AppActivate(LPCTSTR windowTitle){

    // Get first window on desktop
    HWND firstwindow = FindWindowEx(NULL, NULL, NULL, NULL);
    HWND window = firstwindow;
    TCHAR windowtext[MAX_PATH];

    // Guard against search word matching current console title
    TCHAR consoletitle[MAX_PATH];
    GetConsoleTitle(consoletitle, MAX_PATH);

    while (1){
        // Check window title for a match
        GetWindowText(window, windowtext, MAX_PATH);
        if (strstr(windowtext, windowTitle) != NULL && strcmp(windowtext, consoletitle) != 0){
            break;
        }

        // Get next window
        window = FindWindowEx(NULL, window, NULL, NULL);
        if (window == NULL || window == firstwindow){
            fprintf(stderr, "Window not found\n");
        }
    }
    fprintf(stderr, "Window found: %s\n", windowtext);

    // Bring specified window into focus
    AllowSetForegroundWindow(true);
    ShowWindow(window, SW_RESTORE);
    SetForegroundWindow(window);
    SetFocus(window);
}

int main(int argc, char* argv[]){
    AppActivate("Ikaruga");

    Sleep(2000);

    // Create a generic keyboard event structure
    INPUT ip;
    ip.type = INPUT_KEYBOARD;
    ip.ki.wVk = 0; // scan code for 's'
    ip.ki.time = 0;
    ip.ki.dwExtraInfo = 0;


    while (1){
        // Press the "S" key
        ip.ki.wScan = 0x1F; // 0x1F 's'
        ip.ki.dwFlags = 0; // 0 for key press
        SendInput(1, &ip, sizeof(INPUT));

        // Release the "S" key
        ip.ki.wScan = 0x1F;
        ip.ki.dwFlags = KEYEVENTF_KEYUP;
        SendInput(1, &ip, sizeof(INPUT));

        char msgbuf[200];
        sprintf(msgbuf, "Pressing S\n");
        OutputDebugString(msgbuf);

        Sleep(2000);
    }

    return 0;
}

Edit: I forgot to mention that I've tried setting the code on both wVK/wScan and 's' vs 0x53.