Undyne's Spear is blockable using the down arrow! Toriel's Fireball always comes from the top and will not hit you if you are >80 damage taken. Sans' Bone is like a boomerang. Mouse Pointer to move! Don't get to 100 Damage Taken!
USE DOWN ARROW TO TURN SHIELD I made this in 2hrs without ever playing Undertale in my life before... Credits: Toby Fox-Undertale and Bring it in Guys! Undertale (HEAVILY INSPIRED)