How does this Game Maker-like c program look

I made this today and I am wondering if there is a better way of making a Game Maker-like game using SDL.

Code:

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#include <stdio.h>
#include <stdlib.h>

enum entitytype_enum {
        SPRITE = 1,
        BACKGROUND,
        ROOM,
        OBJECT,
        INSTANCE
};

typedef struct Entity {
        int type;
        /*
    SDL_Surface *image;
        SDL_Rect *rects;
    */
    int cols, rows; /* These variables are for sprite sheets */
        int x, y;
        struct Entity *sprite;
        struct Entity *instances;
        struct Entity *next;
} Entity;

Entity *startEntity = NULL;

Entity *newEntity(int type) {
        Entity *entity = (Entity*)malloc(sizeof(Entity));
        entity->type = type;
        /*
    entity->image = NULL;
    entity->rects = NULL;
    */
        entity->cols = 0;
        entity->rows = 0;
        entity->sprite = NULL;
        entity->instances = NULL;
        entity->next = NULL;
        if (startEntity == NULL) {
                startEntity = entity;
        } else {
                Entity *tmp = startEntity;
                while (tmp->next != NULL) tmp = tmp->next;
                tmp->next = entity;
        }
        return entity;
}

void freeEntities() {
        Entity *current = startEntity;
        while (current != NULL) {
                Entity *tmp = current->next;
                /*
                if (current->image != NULL) {
                        SDL_FreeSurface(current->image);
                }
                */
                free(current);
                current = tmp;
        }
}

Entity *getEntity(int type, int index) {
        Entity *current = startEntity;
        int i = 0;
        while (current != NULL) {
                if (current->type == type) {
                        if (i == index) break;
                        ++i;
                }
                current = current->next;
        }
        return current;
}

int main(int argc, char *argv[]) {
        newEntity(SPRITE);
        newEntity(BACKGROUND);
        newEntity(ROOM);
        newEntity(OBJECT);
    newEntity(ROOM);
        if (getEntity(ROOM, 0)->type == ROOM) printf("ROOM 0 = ROOM");
        freeEntities();
        return 0;
}

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