C#编写一个大字母游戏，详细代码，不懂问博主。。。。

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Media;

namespace dazimuyouxi_2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        int i = 0, j = 0;

        private void Form1_Load(object sender, EventArgs e)
        {
            label1.BackColor = Color.Green;
            label2.BackColor = Color.Red;
            label1.Text = "分数：" + i;
            label2.Text = "错误：" + j;
            this.KeyPress += Form1_KeyPress;
            this.comboBox1.SelectedIndex = 0;
        }
        bool istrue = true;
        SoundPlayer s = new SoundPlayer("GRAY2WEA.WAV");
        private void Form1_KeyPress(object sender, KeyPressEventArgs e)
        {

            foreach (Control item in Panel1.Controls)
            {
                if (item.Text == e.KeyChar.ToString().ToUpper())
                {
                    if (istrue == true)
                    {
                        item.Tag = "bj";
                        feiji.Location = new Point(new Size(item.Left + item.Width / 2 - feiji.Width / 2, feiji.Top));
                        Label zd = new Label();
                        zd.Size = new Size(40, 40);
                        zd.Location = new Point(new Size(feiji.Left + feiji.Width / 2 - zd.Width / 2 + 20, feiji.Top));
                        zd.Text = item.Text;
                        zd.Tag = "zidan";
                        zd.Image = imageList2.Images[0];
                        zd.AutoSize = true;
                        Panel1.Controls.Add(zd);
                        istrue = false;
                    }
                }
            }
        }
        Random a = new Random();
        private void timer1_Tick(object sender, EventArgs e)
        {
            Label lab = new Label();
            lab.BackColor = Color.Transparent;
            lab.Size = new Size(20, 20);
            lab.Text = Convert.ToChar(a.Next(65, 91)).ToString();
            lab.ForeColor = Color.FromArgb(a.Next(256), a.Next(256), a.Next(256));
            lab.Font = new Font("微软雅黑", 20);
            lab.Location = new Point(new Size(a.Next(0, Panel1.Width - lab.Width - 10), 0));
            lab.AutoSize = true;
            lab.Tag = "zimu";
            this.Panel1.Controls.Add(lab);
        }
        private void timer2_Tick(object sender, EventArgs e)
        {
            foreach (Control item in Panel1.Controls)
            {
                if (item.GetType().Name == "Label")
                {
                    if (item.Tag.ToString() == "zimu" || item.Tag.ToString() == "bj")
                    {
                        item.Top += 5;
                        if (item.Bottom >= feiji.Top)
                        {
                            item.Dispose();
                            j += 1;
                            label2.Text = "错误：" + j;
                        }
                    }
                    if (item.Tag.ToString() == "zidan")
                    {
                        item.Top -= 20;
                        foreach (Control xz in Panel1.Controls)
                        {
                            if (xz.GetType().Name == "Label")
                            {
                                if (xz.Tag.ToString() == "bj")
                                {
                                    if (xz.Bottom >= item.Top)
                                    {
                                        PictureBox pb = new PictureBox();
                                        pb.Image = imageList1.Images[0];
                                        pb.BackColor = Color.Transparent;
                                        pb.Location = item.Location;
                                        pb.Tag = 0;
                                        pb.Size = new Size(30, 30);
                                        pb.SizeMode = PictureBoxSizeMode.StretchImage;
                                        //pb.BackColor = Color.Red;
                                        Panel1.Controls.Add(pb);
                                        timer3.Start();
                                        s.Play();
                                        item.Tag = 0;
                                        xz.Dispose();
                                        item.Dispose();
                                        i += 1;
                                        label1.Text = "分数：" + i;
                                        istrue = true;
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }

        private void timer3_Tick(object sender, EventArgs e)
        {
            foreach (Control item in Panel1.Controls)
            {
                if (item.GetType().Name == "PictureBox" && item.Tag != null)
                {
                    int n = int.Parse(item.Tag.ToString());
                    n++;
                    if (n > 26)
                    {
                        item.Dispose();
                        return;
                    }
                    ((PictureBox)item).Image = imageList1.Images[n];
                    ((PictureBox)item).Tag = n;
                }
            }
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            comboBox1.DropDownStyle = ComboBoxStyle.DropDownList;
            if (comboBox1.Text == "长平之战")
            {
                this.BackgroundImage = new Bitmap("2.jpg");
            }
            if (comboBox1.Text == "赤壁之战")
            {
                this.BackgroundImage = new Bitmap("3.jpg");
            }
            if (comboBox1.Text == "蓝色星球")
            {
                this.BackgroundImage = Image.FromFile("1.jpg");
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (button1.Text == "开始")
            {
                timer1.Start();
                timer2.Start();
                button1.Text = "暂停";
            }
            else
            {
                button1.Text = "开始";
                timer1.Stop();
                timer2.Stop();
            }
        }

        private void timer4_Tick(object sender, EventArgs e)
        {

            foreach (Control item in Panel1.Controls)
            {
                if (item.GetType().Name == "Label" && item.Tag.ToString() == "zidan")
                {
                    item.BackColor = Color.Transparent;
                    int m = int.Parse(((Label)item).Image.Tag.ToString());
                    m++;
                    if (m > 3)
                    {
                        item.Dispose();
                        return;
                    }
                    ((Label)item).Image = imageList2.Images[m];
                    ((Label)item).Image.Tag = m;
                }
            }
        }
    }
}