Category: game design

Soo… one of the things about doing a reverse tower-defence mode in my game, is that suddenly you care more about the route your troops take. In tower defence, the fact that enemies may seem to mindlessly go off on a tangent doesn’t matter. If they act dumb then yay! if they act clever then yikes! but it’s never frustrating.

As attacker, things change. if a left turn goes to certain death, you expect your units to take the right turn. But is it that simple? Maybe left is lethal to infantry, but right lethal to tanks. Maybe you want to send the infantry to their deaths as a decoy etc. Consider the following map:

In terms of general design and gameplay, I love this. it makes for huge flexibility, unpredictability, and variety. As a player, I can find it frustrating when attacking because the troops may take a route I don’t want them to take. I’ve been mulling over various GUI ideas for issuing orders. None are perfect, and in any case, I’m keen to have GSB-style hands-off play for challenges, which means too many mid-battle controls are going to be a pain.

I can’t yet decide whether it really is frustrating as a player if the routes are chosen by each unit, or if that’s just me as designer panicking. The instinct is to add all sorts of options or UI controls, but I don’t want this game to be complex to play. Hmmmm…..

On a lighter note.

The last few days have seen nothing but multiple xperiments with reconfiguring the gameplay for Gratuitous Tank Battles until I hit the magic balance of excitement, fun and spectacle. This game design business is tricky stuff!

Tower defense is an accepted, well-known formula, but tower ‘attack’ is not, and at the very least, I want to ship a game that is fun to play as both attacker and defender in tower-defense style. So with that in mind, I played the game a lot and concluded that it had lots of design issues. The main one was traffic jams. I was trying to design a simple ‘starter’ map that had a single weaving path between towers, and you would place your units and away they would march. The problem was, that when you spot a certain difficult tower ahead, it’s all very well placing a unit that you think counters it, but that unit is then stuck behind 15 other units before it gets there.

Initially I’d been scared of multiple paths for all maps, because of the complexity for the player, frantically scrolling around. Then I realised that if the paths were vaguely parallel, this problem went away. if I shrunk down the map a bit, I could fit the whole screen in with one look (when zoomed out), and could get more of a grip on it, even with multiple paths.

There have been a whole host of other changes as a result. Lots of balance changes, plus the introduction of ‘supply drops’ which automatically drop on the path in the quietest areas of the map, thus encouraging the attacker to spread his attack over multiple routes. That seems to work, as it’s a nice trade-off between ‘those supplies look tempting’ and ‘I ‘m kinda fully committed to attacking this route instead’. Parallel groups of paths also encourage complementary units, so repair wagons can trundle along beside assault mechs, etc, and a sluggish or damaged tank doesn’t bring the whole army to a halt (just half of it :D) I have full support for units stepping sideways around such blockages, I just need to try it and see how it goes.

I have some crappy placeholder art still in the game, and tons to do, but the last few days, where I’ve totally ignored graphics and only fiddled with mechanics and balance, seems to be paying off nicely. It feels more like a game now, and less like a tech demo. I also ditched fog of war, although it may well return in certain modes.

Everyone agrees that when it comes to gameplay the best approach is to try tons of stuff and see what turns up right?
Anyway, it’s an approach I am becoming keen on. Things often sound like the greatest game idea in the world until you try them. And things that sound lame and boring often turn out to be hilarious and fun. The ski-jumping game in wii-sports probably sounds crap in the design document…

Anyway, with that in mind, after playing through a few GTB battles in ‘classic’ mode (tower defense) as the defender, it became clear to me that ‘towers that do different damage to different units’ isn’t enough, in terms of interesting decision and gameplay, so I started thinking about special units.

As of today, there are 3 new magic modules, and associated units in the game. They are hospital modules/ambulances repairyards/trucks and supply trucks. The hospital and repair facilities regularly pulse out waves in a set radius that heal/repair your troops/tanks/turrets as appropriate. There is no overlap, so ambulances only work on infantry, whereas repair yards and trucks do everything else.

This is my first new mechanic, in that we now have units that act as support units, rather than directly contributing to victory. This brings up all kinds of decisions regarding whether to deliberately target the support units, whether you have lots of support units to keep a few big ‘tank’ units alive, or go for a mad rush with no support etc…

The second new mechanic comes from supply trucks. Supply trucks have no weapons, and no abilities, but they score disproportionately when determining victory for the attacker. Basically, getting a single infantryman off the map alive earns (for example) 1 point. get a tank away and you earn 50 points, but get a supply truck away and you earn 500 points :D

This introduces some new things to strategize over. supply trucks are literally harmless when they enter the map, and only pose a real threat as they close in on the exits. Unlike normal units, which can serve some purpose in shooting turrets etc, the supply truck is a binary decision. In other words, you should only deploy one if you are SURE its going to make it to that exit.

Obviously there are tons more potential ideas, and nothing here is revolutionary, but I hope to eventually ship a game that gives the player a ton of variety. Small tower defense battles, as attacker or defender, big battles, rush battles, wave-battles, 2-sided pitched battles, custom edited maps…. If I don’t die from stress or old age before I finish all this :D

I’ve been doing some playthroughs of various gameplay modes in GTB and thinking a lot about the game design, and the way units interact.

One of the core things that makes Tower Defense games playable, and casual (to a degree) is the clarity of how units interact. There is often a clear way of differentiating how the units work against each other. For example, gun turrets are good against ground units, lightning turrets are good against flying units, laser turrets are not-bad against both. Often that sort of data is as complex as it gets. You can then have an upgraded ‘level II’ laser tower that is the same, but better, and so on…

One of the unique selling points of GTB is that towers have individual modules that can be combined, so it’s not as simple or inflexible as normal. In theory you could customise your defenses to do exactly what you liked. The trouble with this is it over-complicates things and makes the game less playable for first-timers and casual players.

I’m thinking right now that this is fine, as long as it’s clear what MODULE achieves what, and as long as it’s clear that the different classes of unit (Turret/Mech/Tank/Infantry) still have definite characteristics.

In other words, when you see a bunch of enemy infantry, it needs to be obvious that you think “right, I now need to build tower X”. This is where GSB let itself down.

So… in terms of broad principles:

• Lasers are good against armor, bad against shields.
• Ballistic weapons are good against shields, bad against armor
• Missiles are generally average at everything, but have splash damage

In addition to that, I’m thinking of some hard coding so that:

• Machineguns are rubbish against everything except infantry, where they are devastating.
• Flamethrowers are the same as machineguns, plus they have splash damage.
• Bigger weapons (all turrets, and mech/tank weapons) are relatively poor against infantry.
• Infantry weapons are relatively good against each other.

That will mean some code changes. In addition, I’m more heavily skewing things so that:

• Tanks do not have shields of any kind. Tanks are all about armor.
• Mechs have the best lasers and the best shields.

Plus also:

• I’m adding in construction times for turrets, so you can’t insta-place a turret.
• You still cannot destroy a tower and reclaim some of the cost. Is this important? I never do it, but some people do. Not sure…
• You can design (then use immediately) new units mid-battle. Maybe that is a bad idea?

There are a multitude of other things. I’m of the opinion that pretty much *all* maps should have at least two routes, so when you are placing attacking units, it’s a constant game of ‘aha, I see the right-side route is ill-defended against infantry….’ Obviously the first tutorialish map should be simpler.

I do wonder if I should put together a really early playable alpha of the game without any of the fancy graphics, just to let people play with the mechanics and offer feedback. If the majority of music / graphics aren’t even in the game, I could do that without fear of piracy or people confusing it with a finished game, and make it free. Hmmmm. I just don’t know… Would mean a nightmare load of separating stuff out… I wish I’d thought of that 6 months ago.