Secret 1 - Serious Damage
In one of the first houses, you hear a door creaking. Blast it to get a serious damage.
Secret 2 - Secret Running Santa
Pulling the switch on the windmill frees the running santa claus.
Shoot him slowly to get some goodies out of his bag. You get different combinations of goodies, so if the ones you get don't appear helpful, try again.
Secret 3 - Granpa Frost
In the roof of one of the last houses here, you find a jammed santa claus. Free him with a rocket to win a super health.
Secret 4 - Secret Snowman
Behind the jammed granpa, there's another snowman. Blast it to free a small armor.
Secret 5 - Secret Running Santa
After having finished the next valley, you get to another small town. Here, activate the switch on this snow man to free another running santa claus. Hell give you some more free items.
Secret 6 - Snowman Avenger
Some steps away, you find an armor in front of a snowman. As soon as you take the armor, the snowman will show his rockets. Blast him.
Secret 7 - Secret Items
Here, you also find another house with a creaking door. Blast it to get some power-ups.
Secret 8 - Secret Shrinking Snowman
Just before entering the cave, you have to give this snowman 6 rockets or grenades. It will shrink from the first five ones. Then, from the sixth, it will dissappear and three bio mechs will spawn instead. Thus, it's good for your health to send the sixth rocket from the cave entrance.
Secret 9 - Secret Health
After having passed the bridge that breaks, you can turn round and jump into the gap. This teleports you to a super health.
Secret 10 - Secret Ammo
In the next hall from the place where you get this health pack you can see something shining on a rock above you. You won't get up there, so bring it down.
Secret 11 - Secret Weapon
Before exiting this hall, walk into a very dark spot to the left. You have to crouch a bit to get the cannon.
A beautiful place to climb around a bit
Secret 12 - Secret Armor
From the bridge (secret below) you see a place you should have visited before. It'll hurt a bit anyway, so you can do it now, too. Get down there, jump through the lava and grab the super armor.
Tips & Tricks
beagz found a trick to get the armor without taking any damage: If you look at the screenshot above, in the bottom left you see 3 platforms in the lava that you crossed over earlier. If you jump onto the one that is positioned just above the 5 it will take you on a nice tour around the lava including getting you close enough to jump to secret 12 without damage and then jump back on it to complete the tour. Thanks for this great advice!
Secret 13 - Secret Health
Under this Sergio Leone style bridge you'll find a secret health.
