The gameplay of Snow Bros. is similar to Bubble Bobble, released in 1986. The game supports up to two players, with each player taking the part of one of two snowmen, Nick and Tom. Each player can throw snow at the enemies. The player must throw snow at each enemy until it is completely covered and turns into a snowball. An enemy partially covered in snow cannot move until it shakes it off.
Once an enemy has been turned into a snowball, the player can roll it. The snowball will rebound off of walls until eventually shattering against a wall. Any enemies the snowball rolls into are eliminated and other stationary snowballs start rolling when the rolling snowball touches them. If the player manages to take out all of the enemies with kicking one snowball (this one snowball may be used to make others bounce around as well and increase the chances to pull this trick off), bonus money will fall from the sky.
Every tenth level there is a boss. Each boss can sustain being hit a number of times. In the Sega Mega Drive port, after the 50th level, you play as one of the snow castle princesses.
When a player bowls an enemy over, it may drop a potion bottle. The color of the potion lets the player know what special power-up he or she will acquire:
- Red increases walking speed.
- Blue increases the amount of snow thrown, thus making it easier to cover an enemy in the snow.
- Yellow increases the distance that snow can be thrown.
- Green causes your character to inflate like a balloon while having the ability to fly around the screen and knock out enemies for a limited period of time.
The effects of the red, blue, and yellow potion wear off after the player loses a life. Also, both the Blue and Yellow Potions increase the power of the snow thrown from either Nick or Tom.
If the player takes too much time to complete a level an evil pumpkin head will come and try to kill the player character. It is invincible but can be stunned and sent to appear elsewhere in the level with snowballs or snow shots. After a short time, the evil pumpkin will spawn ghosts that can travel freely through the level and seek the player character. These ghosts can’t be killed or stunned, so the player’s only hope is to avoid them while eliminating the rest of the enemies to move on to the next screen as soon as possible.