This brief guide is assuming you have around an hours playtime on the game and know the basics.

To make things easier to explain I'm going to use control keys w, a, s & d
If you use the arrow keys you can convert this by assuming:

w = up
a = left
s = down
d = right

One of the most useful thing I learnt is how to stay down while continuing to attack from left to right. You can do this by pressing "a, s, d" repidly in repeat, or "d, s, a" will also work too. This will enable you to keep attacking from left to right (or right to left) while staying down. This is good for ducking thrown axes & pogo stick while still being able to attack.

Whenever you jump you should never just land. Always turn a jump into a down attack. This will prevent any close enemies that have already started an attack hitting you when you land. The down attack also works well against chainsaws or rockets that are going along the floor. You only have to wait till they have slightly passed you before you can safely use this attack on them and you can almost land directly on top of them using this attack without them hurting you.

One of the strongest and longest attacks you can use is the split kick, so you should use this often (it will also knock enemy's back). Just jump then attack in the opposite direction of what you are facing. So for example if you are facing left just press wd, if you are facing right It's wa. This is particularly good for getting weapons from pogo's as it will kill them in one hit.

Use your spin kick often by pressing up twice (w,w) this is good for hitting any enemies you've knocked into the air with an uppercut, or passing rockets. It is always worth trying to deal with rockets on their first two passes above you, before they do the ground sweep (third pass) which can be more awkward to deal with.

Always grab as many weapons as you can, you should wait till pogo's/chainsaws are close enough for you to grab their weapons before you attack them to make sure you can recover their weapons. Also remember a weapon can only hit 3 enemies before it breaks but it can knock back (deflect) an unlimited amount of projectiles (thrown axes/other dropped weapons) without using any of it's 3 "hits".

Finally if you're dealing with multiple enemies coming from one direction, lets say left, don't just hit a a a a a to hit straight left, instead try mixing the left attack with a down attack, so it would be a, s, a, s, a... This is a stronger and faster attack, also I find it less demanding on the hand as you can use two fingers instead of one.

These are the most useful things I have learnt on the game in my 5hrs playtime and have enabled me to be hitting around 200-250, I hope they can help you out too...

Please comment and rate if this helps you out.