| knight & monster | Bts Evan (evanbts2833@gmail.com) (a young student talented in drawing) |
| bulb | http://freepngdownload.com/bulb/bulb-free-png By freepngdownload.com attribution required |
| tank | https://clipartxtras.com/download/e5b3e9645bbf80fe975bda85ee737f2aa7ce7831.html attribution required |
| flag | https://clipartxtras.com/download/45c94b8da84fb5eec25057756c943b38bfcc0bb0.html attribution required |
| mole | https://pixabay.com/en/animal-mole-underground-furry-158236/ Creative Commons |
| tank sound | http://soundbible.com/1325-Tank.html attribution required |
| ding sound | https://freesound.org/people/suzenako/sounds/320905/ attribution required |
| footstep sound | https://www.zapsplat.com/music/golf-club-swing-hit-ball-shot-3/ attribution required |
| ta da sound | http://soundbible.com/1003-Ta-Da.html attribution required |
| failure sound | https://www.soundjay.com/failure-sound-effect.html free to use |
| switch sound | http://soundbible.com/772-Button.html attribution required |
| siren sound | http://soundbible.com/1511-Fire-Truck-Siren.html attribution required |
| football | https://vector.me/browse/181292/soccer_ball_clip_art Image Credit: Soccer Ball Clip Art from Vector.me (by Gioppino) |
| bomb | https://ya-webdesign.com |
| explosion | https://gifer.com/en/3iCN |
| explosion sound | https://freesound.org/people/Zangrutz/sounds/155235/ attribution required |