Terror means this:

• You can whip through walls.

• I guess the mortar trick means you can fire a mortar vertically up, and when it comes down, you can just jump through it (if you're good). This one was already implied by “You won't collide with projectiles while you are in mid-air”

Amateur Hour:

• Parachute deploys automatically.
• Hammer, Shoryuken, Whip and Bat don't only work on Hedgehogs.
• Hammer, Shoryuken, Whip, and Bat hit a little bit behind your hog as well.
• Notes can be played during piano strike using the F1-F10 keys.
• Rope, Flying Saucer, Birdy and ice can also be used to knock other hedgehogs.
• You can set a timer on Drill Strike.
• Sniper Rifle does more damage the further away it is.

Good to know:

• Cleaver does more damage the faster it's moving.
• Kamikaze, Shoryuken, SineGun, Mine, Flying Saucer, Dynamite, Portal Gun, Pickhammer and Teleport can be fired mid-air.
• Thus, for lack of a parachute, a timed Shoryuken or PickHammer can cancel fall damage.
• Portals can be fired through drill rocket AND deagle holes.
• You can knock hedgehogs (esp. on slopes) by jumping out from under them.

Just giving away the best tricks, here:

• You can resurrect enemy hogs to 1 life and kill them alongside other hogs for bonus damage.
• You can "drop" cake.
• You can save HP by transferring it from sick hogs to dead ones via Resurrector.
• Cake and Homing Bee aren't the only weapons that work underwater.
• Girder can extend the reach of Drill Rocket.
• Hog momentum is preserved upon teleport.

I just had an idea: Why not taking the best tips from this thread and include them to the list of tips shown in the main menu?

I wouldn't include most beginner-type tips for weapons, because they can be already seen in-game, and this would just be redundant.

Edit: I have just edited tips_en.xml, here's the updated version:

http://lpaste.net/raw/140120

I added some of the tips on this page and added some new ones. I also made 2 URLs clickable and fixed typos and typography.

New tips (in tips_en.xml):

• Dud mines are not harmless: Although their timer is broken, they can still explode if they took to much abuse!
• Love is hot! Use Seduction to thaw frozen hedgehogs.
• Smoke coming from a barrel is an indicator that it is low on “health” and even small amounts of damage might cause it to burst.
• In King Mode, your king will start out healthier, stronger and more resistant to damage and blows than the minions.
• In King Mode, the king will take damage each turn when there are no minions left in the team.
• Don’t stand still on an icy slope, or you will slip away. Alternatively, you can hold down [precise].
• In the lands of Snow and Christmas, the snow piles up over time, unless the land is indestructible.
• Be aware in lands of Snow and Christmas, because girders are made of slippery ice.
• The retreat time depends on the weapon you used. Be careful, some weapons don’t have a retreat time and immediately end your turn!

Old tips, rewritten for tips_en.xml:

• Barrels start with 60 health and take damage like hedgehogs, so they need some abuse until they explode.
• Need more bounce power? Change the bounce strength of grenades, cluster bombs, old limburgers and mines while holding [precise] and pressing one of the timer keys.
• Did you forget the goals or game modifiers inside the game? Hit the pause or quit key to review them again!
• You can punch, whip and hammer other things than just hedgehogs. Hit them all!
• If not mentioned otherwise, mines normally explode after 3 seconds.
• The whip also hits hedgehogs and objects behind a thin wall.
• A cleaver deals more damage the faster it’s moving.
• You can drop cakes from cliffs, but you have to stand very close to the edge, so be careful.
• Use your rope to push away other hedgehogs i.e. by slding on the ground. This technique is known as “rope-knocking”.

Edit: The suggested tips have been included into Hedgewars! They will appear in the next version.

Here's a new interesting fact I just learned about:

• If you launch a projectile from the water while in the flying saucer (with [Precise] + [Attack] keys), you get four times the usual retreat time

WRT barrel smoke, the smoke is white when there is more than 30hp and black at less.
This means you have some idea as to what might be safe to do to it, for example whipping.

Note that a barrel in snow can still blow up in a situation like that due to being stuck and a firepunch banging it against the snow.

>Thus, for lack of a parachute, a timed Shoryuken or PickHammer can cancel fall damage.

Sine gun fine too

skip turn for safier landing

unc0rr fixed in 0.9.23
thanks for the report

Most of the gameplay information in this thread has been added to the Unofficial Hedgewars Wiki by me:

http://wiki.hedgewars.wohlnet.ru/wiki/Gameplay_odds_and_ends

This page is intended only for the not-so-well-known rules, not for strategic advice. I or someone else might create a seperate wiki page just for tips and tricks. Some players might figure out their stretegy on their own, so I want to keep these things seperate.