Short game but I enjoyed it.
On points; Like many have said, invest most all your first points in digging. You'll definately need the materials to advance so it's a buy now benefit alot later investment. Throw a few in speed so that you can get to and from the digging spots as time doesn't stop. You'll also need a little speed to fight the giant worm at the end. Afterward when you can dig fairly quickly, divide your next points between vitality and gunsmithing.
My preference was to let dexterity and armor be least important when it came to giving points. Dexterity just affects accuracy, majority of weapons are automatic anyway, and usually enemies will be close to you quickly (2 or more, that usually means time to get back to base) so it only needs a certain amount. Armor just needs enough to keep from dying very quickly plus armor items grant a reasonable bonus anyway. Creatures can't hit you if you kill them so let gunsmithing be your armor.
Where to spend materials; Starting out my first investment was to fire the starting pistol like crazy, and save until I could afford a rifle, recycling my pistol. After that I invested in my base buying the barb wire, then the medium cannon. Combined they killed alot of things during the nights, and really helped my experience level.
I stuck with my rifle and the next day I bought the best armor I could get, next to the highest.
As far as specific materials go, the large ration packs that are a better investment than buying 4 small ones. I would just let my hunger get almost to zero and use one. Anyway, I seemed to have more medicine than I needed, so I stocked up on the lowest health packs. Toward the end I resorted to them to help my hunger levels since they benefit it too.
The Base; The last few days, invest in the best cannons, healing ability, and armor for your base as you can. They don't only help your base. Every time your base kills a creature at night, it adds to your own experience which means a stronger character. In my opinion upgrading your base is one of the best investments of materials.
Digging; It seems that around 5:45am is the time to leave the base. At that time there should still be some creatures attacking, don't wait on them. If not full, stock up your health with pills and make sure to carry some sort of food if there's any chance your hunger will go to zero while you are out. Get healed, get fed, kill those enemies and head toward digging sites, shooting everything along the way. Soon enough they will be gone and you can dig. Work fast as you can.
Toward the end of the day, the first enemy you see usually means you only have time to work 2 more squares, quickly. Do it and then beeline back to base unless you want to try and run-and-gun. Even then be near base, it grants you a free helper to kill enemies.
KILLING THE WORM; Killing the worm isn't impossible, but the more you damage it the harder it gets. Before anything, 1. Keep your distance from it. 2. Let it crawl back into the ground before when leaving the base to fight it. 3. Carry lots of health items with you when you do fight it. 4.The base itself doesn't seem to target the worm, but can hit it when it is in the way of another creature.
First off, it fires a single fireball. It's fairly easy to dodge, just run when it emergers so you always have some range from it (on the very edge of the screen) Dodge and fire at the same time.
Second it will begin firing two fireballs in a split. Just get range from it, and stand still so they pass you.
Lastly it will begin to fire 3. This is the tricky part, and a fullon blast takes away most of your health. You can try to dodge, but it is very hard. Plus the range you need usually means you won't have it on your screen, making hitting it difficult.
Instead try this. There are certain large rocks around your base you can use for cover. Get that big rock between you and it. Let it attack, make sure you don't get hit, then pop out quick and fire some rounds at it. Keep cover. Soon, Dead Worm. You Win. Congratz.