what is GravityJAM?

a brief history of mine

Back when computers were real computers, when games ran on thin air, determination and clever ideas I came across a game that was so re-playable that for the longest of time it was loaded on my Amiga 600 more often than FlashBack... It was a great game and it was called 'Gravity Power'.

The game, i found out later, was by no means an original concept - in fact it was the clone of a clone. Originally there was a game called 'Thrust', then 'Gravity Force' and then 'Gravity Force II' (an unofficial sequel). The game i actually played was called 'Gravity Power' because it was release by the magazine 'Amiga Power' (with a few tweaks and additions they amalgamated the name). The reason why i will refer to my game as a 'Gravity Force II' clone is because (as far as i'm aware) it was only the sequel (in my view) that added features that gave the game it's great playability - namely the ability to play against a friend.

Anyway, enough from me I hope you have fun ;)

Phil Glanville

upgrades, languages and time

After unwillingly having to upgrade from my Amiga to more modern equivalents i always half expected it to turn up again at some point on a large scale but it never seem to.

With the non-existence (well none that i could find) of a real PC version i always fancied the idea of making my own. In fact whenever i sat down with a new programming language (Amos, Blitz Basic, Java, C++, JavaScript, ActionScript) if i found the time i would always play around with creating a clone - it actually makes for a great target to use in learning a language - sadly though, as per usual, i am always run off my feet so i never had the time to spend to get the idea of the ground.

.. that was until recently, when i discovered the advances made in ActionScript to do with BitmapData. Now i have always loved Flash for it's speed of development, a great front end coupled with the power of JavaScript is never going to go wrong... it's only downside was that it was never technical enough or fast enough to handle certain aspects of coding. That seems now to have changed a great deal, and i am currently enjoying learning ActionScript 3 (although a little exasperated at the number of changes from 2) - in fact i hope soon to have constructed a full http network capability in AS3 so i can get rid of the split screen problem - which is something that could never have worked properly before (well not without some hideous hacking).

How do I play?

for those who have yet to...

The concept uses a few simple rules that combine to create a unique game each time (especially when played against a human player) as even though when playing you are only altering a few variables those variables give enough scope to make every round quite different.

You control a small triangular ship who's whole existence pivots around the destruction of another small triangular ship. This doesn't mean you have only one enemy however. Once in the game even the landscape can be a formidable opponent, that is if you don't learn to do battle with everyone's age-old nemisis... Gravity.

To put it simply, the UP key controls thrust, the LEFT and RIGHT keys control your direction (or angle) - you'll find for the most part that the best angles for survival lay somewhere between 10 and 2 on the face of an analog clock... and it's best to save FUEL (and not go crashing into everything) by pulsing the thrust rather than all out rocketing... but then again survival isn't the only thing worth worrying about and a great deal of manouvers can be achieved using the whole 360 degrees and a bit of quick thinking :)

The DOWN and FIRE keys are used with ITEMs, although the DOWN key can also access the EQUIP MENU and other MENUs but only when landed in certain locations. All your equiped ITEMs are shown in the box(es) to the bottom left and right of the screen. The current ITEM selected for use is highlighted by an orange glow - you can change which one is highlighted by using the ITEM NEXT and ITEM PREVIOUS keys (for player one by default these are '[' and ']').

When you first load in to the game you wont have any ITEMs equipped and if you plan to do any damage at all (that doesn't involve kamakazi stunts) then i'd press DOWN and navigate the EQUIP MENU before you take off. Navigation of EQUIP MENU is pretty straight forward - use your UP and DOWN keys to highlight a different equipment slot (if you have more than one) and the LEFT and RIGHT keys to rotate what ITEM you want to equip in that slot. Once you are done equiping press the FIRE key to exit the menu.

Obviously i can't tell you how you *should* play the game, so all that is left for me to say is... try out different techniques and weapons and most of all go explode() your oponent :D

[ Play the Demo ]

GravityJAM is © phil glanville - unabacus design 2008

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If you've liked what you've seen so far then watch this space, i have a huge number of ideas for GravityJAM and ideas for other Online Games (i just never have enough time) - if you'd like to keep your ear to the ground then sign-up here and receive sporadic news updates :)

I will also link this in (later on) as your game identity to log game stats and things so it's worth signing up anyway if just to register your chosen username or game id. ;)


For those who are still alive

I've never been a great one for following rules, not that i like to cause problems - far from it - it's more that they don't tend to make a lot of sense to me in my own little world. So please if I have infringed any rights or trampled someone elses picnic then let me know as it was never my intention...


one week

Now i've mentioned the fast pace that you can achieve when working with Flash but i never expected to have got so far with this game so quickly; but i guess it was all my previous attempts in other environments.. but the current version of the game you are playing now was developed in one week. Now some out there may say that it shows, and sure it's no where near polished yet... but i hope at least most will like what i've managed so far. Either way i would love to hear peoples comments... leave a message here

key example

player one defaults

The above is the default key layout for player one (all keys can be changed at the setup stage). Please make sure you read the "How do I Play" section to the left before trying out the demo.. unless you're the type of person who doesn't like reading manuals :)


help i can't play GravityJAM!!

First off, before anything else... make sure you have Flash Player 9 or above installed! 7 or 8 will not do... You can find out which version you have by right clicking in the white square below. The option at the bottom (or top) of the context menu that appears should be in the format "About Adobe Flash Player X" where X is the version.

Obviously there are variations and if there is no version number in the menu option just select the about option itself and you should be presented with version information about your current Flash Player). If you still don't know your version or you have the wrong version click here

If you are having problems with framerate try disabling "Ambience Audio" & "Sound Effects" on the setup screen - or see if you have any other webpages loaded with other high intensity Flash (like advert banners or other games) if so close them down. If you use Internet Explorer and the game seems to load half way but no further try refreshing the page.

If you're problem is none of the above, or isn't solved by my recomendations then please e-mail me at - please don't expect a speedy response however - this game is just a side line project so i can only put so much time in to it.