When you first spawn into the world, you'll notice a bunch of items on the ground. Make sure to pick them up! Your three most important items that you get in the start of your game are your Miniaturizor, Auto-Builder and Plasma Rifle. With the Miniaturizor you can destroy and pickup certain blocks depending on the miniaturizors level. For now you'll need to harvest some trees by right clicking with or without the miniaturizor selected in your toolbar. Once you think you have enough wood, place your Auto-Builder. Open up your Auto-builder's menu and make a few wooden walls and platforms. Dont forget to make your scrap into iron, as you'll need it desperately tonight. When you think you are ready, equip your plasma rifle and go fire-fly hunting. (They're the flying thingies.) If you kill one there is a chance for it to drop a Blue Gem that can be used to make tons of usefull things. Make sure to make as many turrets as you can, and, if you have enough resources, dont be shy to make a Pisma Shotgun. They cost just as much as turrets.

If you want to survive the night, you'll have to have shelter. Just build some basic wood walls around you, tall enough to keep monsters out. Dont forget to place your turrets, they help ALOT. Its always good to have an extra gun by your side. Dont place your turrets on top of your wood walls cause whe n the monsters break through your walls, your turrets come crumbling down with them. (Dont forget that physics still apply in this game!) Do anything you can to keep them out. Soon, the nights will get longer and harder, so dont keep using this strategy. it usually only lasts about the first three nights untill mobs get too strong. Soon, you will unlock new walls and better turrets. Remember, never give up, and keep on diggin'!