This is a continuation from the article with the same name. To have a look at the first one, the link is:
http://www.create-games.com/article.asp?id=751

Basically, the point in this article and the one before it is to help people have an idea of how their game can be more or less successful. What can make or break your game, to put it simply. Here's some more points to consider:

GAME MODES:
I've already discussed multiplayer in the first article, so I'll leave that out here. Games become more interesting if there's several modes. Think along the lines of an arcade mode, which is basically a mode that runs with the same mechanics as a normal mode, but the same level is played forever, or until the player dies. Also think along the lines of skirmish mode for strategy games (pick a level, have all techs, defeat all enemies), time trial for racing games, survival mode (basically an arcade mode but not score-based... kill until killed) for an action game, and things like random level mode (see the first heading in the first article). Modes of play make the game have more replay value, and instantly give it more to offer for a player's tastes.

GRAPHICAL STYLE:
Try to stick with one graphical style, at the most two (think one style for backdrop and one for the rest). It's no good having photo-realistic characters with cartoony blood (think Mortal Kombat)... it just doesn't look right. Your game will be more presentable if you keep it all under the same wing, and it will look infinately better than a mixed bag. That is, of course, unless your game requires the opposite. If you were going to make a game based on Dot (a movie where a cartoon girl walks around in a real world), for example, then it would be perfectly acceptable to have photo-realistic backgrounds and platforms, but cartoon characters. Finally, please, please save yourself the embarrassment of ripping graphics (unless you're making a fan game and it wouldn't be the same without them) to use in your game. Nobody likes a lack of imagination. If you can't draw for nutters, ask for someone to help in the forums. It's that simple, just remember to include their name in the credits!

CONTROL FOCUS:
Try to keep the same controls consistant throughout the game. It's slightly annoying to have a main menu where the options are chosen by mouse, and then the game itself is played with the keyboard. The player has to change the position of his hands, and no player should have to worry about this while playing a game. Consistancy is the key element to make your game's control system as simple as possible. If you press ENTER to accept a menu choice in the main menu, keep it that way for every other menu-based part of your game. If you use a special power with space, make it the same throughout the game. Make it keyboard only, mouse only, or a choice between the two. There are some games that require the mouse as well as the keyboard (ie. scrolling with the keyboard in a strategy game, and activating units / giving orders with the mouse), so don't worry too much if your game is one of them.

PRESENTATION:
Obviously, when you show off your game, you want it to be as well presented as possible. With your main menu, don't have text on the screen saying "press S to start, Q to quit, and H for help". Have a list of options that is chosen by highlighting the choice and pressing ENTER or SPACE or something. When you place the lives and score counters, don't put them just anywhere... think about where it can be placed to cause the least confusion, have the most visibility, and will stand out enough for the player to realize it's actually there. The corners of the screen, or the top and bottom of the screen, are perfect places for counters. And once you've put the counter there for the first level, make sure it's in the same spot for every level following. To make your game look more proffessional, include:

A credits screen - mention things such as sources of music, people that helped with ideas, sound, backgrounds or sprite work.
A help screen - text files are OK, but you can present a help screen better and make headings and things. You can also put images near enemy descriptions or the like. If the player would need a help reference mid-game, it's not nice to quit the game just to go to the help screen. Make a text object, write your help, and convert it to an active object. Then make a single active object with a background and the text pasted over the top, and have that pop up instead.
Mid-game quitting - don't limit the player to quitting only from the main menu, or the standard "press ALT+F4 to quit", give them the option of pressing ESC for a quit prompt. Always have a prompt too, pressing quit by mistake and being booted from the game can ruin many an experience.
High scores - not every game has score, but if it does, you should have a high score screen. There's not much point in getting score if you can't see your best attempt and can't compete against others. Don't just have scores on a single-colour-backdrop screen either, make the high score screen (and any screen, for that matter) interesting with a suitable backdrop, suitable music, and maybe random sound effects.
Website address - at the ending screen, give yourself some credit and have something saying "for more free games from X company, go to www.address-here.com". Don't anger your players by making them have to wait 10 seconds to be able to quit, though. A simple mention is all you need. If you don't want to make an ending screen, put your address in the credits. If people like your game and see your address, they'll want to get more from you, which does wonders for your ego!

IMMERSION:
For people to be immersed properly in your game, you need to make sure that everything suits it. It's hard to be immersed in a horror-based game when the evil zombies and demons make humourous 'BONK!' sounds when you kill them. The music should be fitting, too... and choose a music (or make your own) that adds to the mood you want the game to have. Funky music in an action game sometimes suits it well, but not if you want an adrenaline-pumping, butt-kicking environment. A little thought is all that is needed.

SIZE AND MEMORY USAGE REDUCTION:
There are several methods of reducing the size and memory usage of your game. Here's only a few methods, there's probably several more, too. People often won't download a game if its file size is too big, as most people (especially 56K modem users) won't have the time.

Shrinking - Reduce the size of active objects by clicking on the button that reduces the dimensions (X and Y) of the object down to the minimum. Do this for all of your active objects and you will have reduced the size of your game noticably.
Unnecessary Objects - If there's an active object on the screen that could be substituted with a backdrop object without changing gameplay at all, then do it. Backdrop objects take up much less space.
Image Permanence - If your enemies leave a body behind when you kill them, or you want blood to stay on the floor, shattered crystal fragments to stay and so on, don't make active objects that remain idle. This takes up valuable memory. Instead, draw the blood splatter, body, etc. and make it an active object. Go into the object's properties and uncheck the 'remember background' box. Don't tell it to wipe with a colour, just leave it at that. Now, make an event that destroys the object as soon as it comes into play. This will remove the active object, but print its image on the background below so it still appears to be there.
Audio Snipping - Let's say that you use a sound, but not all of it. For example, in a cutscene you would have an ominous sounding noise, which is cut off by someone speaking. Now, if that ominous sound is, say, 5 seconds long, and you only use 2 seconds of it, that's still an extra 3 seconds of audio that your game needs to contain within it to use it properly. Edit the file you're using for the sound, and cut it after the time you want. This will make the sound only as big as you need, and will cut the size of your game.
Replacing Counters - If there's an active object on the screen that doesn't get destroyed in the game and isn't using its alterable values, then use its values instead of one of your counters. It will save the space that your counter object takes.
Removing Dud Events - Each event in your game takes a little amount of space for your game to 'remember' it. Remove events that are conditions, but have no action.

And there you have it. There may well be a part three to this duo of articles, but it all depends on whether I can think of anything else that's not incredibly straight forward. I probably will. Enjoy, people!

- Rick