Welcome to the mysterious universe of Survive for 21 Days! In this challenging game, you will lead the cute cat miners to collect precious energy minerals, upgrade powerful equipment and tools, and resist the invasion of alien creatures!

How to play:
1. Launch rockets into space, explore unknown planets, and send out your cat miners to mine gold and crystals.
2. Oops, there are a lot of greedy aliens invading! Don't panic, use ores to upgrade a variety of equipment! From electrostatic fields to rays, arm your ship to the teeth.
3. Use the crystals harvested after exploration to recruit more cat miners and upgrade your rockets. With the continuous production of minerals and energy, you will gain more power.

Features:
1. Cartoon and cute space adventure pictures
2. Fun and casual tower defense game process
3. Challenge a longer survival record

Come and join us, start your adventure, create your mining kingdom in the tower defense game, and feel your unlimited imagination!

// Option A //

To download 生存21天 mod from HappyMod.com.
You need enable the option "Unknown Sources".
1. Click on the above link to download 生存21天 mod APK.
2. Save the file in your device Downloads folder.
3. Now tap on Install and wait for the installation to finish.
4. Once it is done, open the game and start playing it right away.

// Option B //

To download 生存21天 from HappyMod APP, you can follow this:
1. Open your browser and download the HappyMod APK file from HappyMod.com - the only official website of HappyMod.
2. Open Android Settings and go into Privacy or Security.
3. Tap the option to Allow Unknown Sources and enable it.
4. Go to your Android downloads and tap the APK file.
5. Follow the directions on the screen to install it.
6. Search 生存21天 in HappyMod App.