General Design Guidelines
Checkpoints were not in the original design of Gunnihilation. Players had five or more health points and took one per hit. In testing we discovered that players would frequently lose all their health immediately then be frustrated by a sudden death after several minutes. Switching to a more modern, instant-death-quick-restart system worked a lot better. This also tied into the health system we adopted for cooperative play.
Generally our guidelines came down to two main elements. Three phases per level with a checkpoint between each phase change, and no more than one minute on average per phase. This resulted in each level having two checkpoints at thirty second to one minute intervals.
The three phases are generally as follows
This is the first phase of the level. Players are presented with a selection of weapons they can choose to use and proceed forward into the level proper. They are presented with a light combat challenge that introduces them to the arena’s layout. They can see where platforms are, where cover is and where enemies are likely to come from.
Often the bulk of the level, the mid-phase kicks into high gear and the player is now faced with the game at its full pace. Often the level would checkpoint after phase 1, allowing them to skip the introductory phase.
After phase 2, the level checkpoints again and gives the player the second challenge for that area. The nature of the third phase varied somewhat, depending on the qualities of phase 2. Phase 3 would usually use different enemies or spawning positions and generally mix things up or throw a little curve ball at the player.
The general rhythm we settled on was thirty second to one minute combat beats. We felt that a minute was generally the amount of time it took for a single fight to start to drag on.
First Mission Breakdown
Because Gunnihilation uses a hub area to select levels players have already been taught how to move, aim and shoot before they get into the game proper. The important thing about this room is A: The player has to move right, jump, aim up, shoot and finally hold down and fall through a platform. This room requires the basic dual stick controls are understood in order to enter the game proper. If the game didn’t have the hub, these features would be built into the first level, most likely using an enemy placed in an unreachable position that the player has to shoot to proceed.
Level 1 – Start with a bang
When the first level opens the player has a nice violent intro sequence, loud and chaotic that sets the mood. (The main inspiration for this sequence was the fantastic opening of Contra Hard Corps). The player can now proceed. Immediately they can kill several weak enemies and are then made to double jump and drop through a platform again, to reinforce the fact that in Gunnihilation platforms are two way (and vital to the game).
We then present the player with the first real help box, telling the player about health (or more accurately, shields). It’s worth noting that in cooperative play shields are removed from the game, so this help box is removed too. Once they are through that, we checkpoint.
The rest of the level is a linear area where they can merrily blast away enemies, with nothing to complicate the process except two larger enemies at the end. These enemies have an indirect attack however, and their projectiles are easily avoided.
Level 2 – Frenzy Tutorial
In Gunnihilation killing enemies fills your Frenzy meter. When it is at least half full the player can activate a special weapon, a giant screen-length purple laser beam. The second level of the game aims to explain this feature to the player by forcing them to fill their meter, activate it and then appreciate its power by mowing down a horde of enemies.
The enemies are shown to the player behind a barrier, letting them see what the threat is and where it will come from before they fight it. A crate dispenser pops out an endless supply of crates containing Frenzy energy, so the player has no trouble quickly filling up their meter. Giving the player this little box to experience their awesome super-weapon early on turned out to be a very effective part of the game, with many players having a good laugh at the carnage they create.
Something to note is that the first level of the game allows the player to gather Frenzy energy from killing enemies, but the enemy count was carefully limited so the player can never actually activate it.
Level 3 – Regular Combat
Here we give the player a regular section of gameplay, with a free refill of their Frenzy meter to let them go to town. This area also bumps the difficulty up a little, and players often found this to be the moment when the bullet hell inspirations of the game become clear. The arena is fairly tight, with no safe corner to retreat to. But the location of each threat is clear, and the enemies are weak.
Level 4 – Special Attacks
The last dedicated tutorial area, which introduces the Shield Bubble. We wanted to avoid killing the player in a tutorial, so the barrier presented to the player is a special bullet type that simply teleports them backward. Players need to drop a shield then drop through the gap it creates.
Level 5 – Regular Combat
The last arena of regular combat, this time it’s larger, with bigger enemies and offers a light introduction to changing geometry, as the arena opens up when enemy spawns are finished off. The challenge is increased again, but the player now has both Frenzy and Shields at their disposal.
This is also one of the first examples of the geometry of the level changing depending on the difficulty setting. On easy or medium the two vertical barriers are removed, giving the player much more space to avoid damage. It is also the first level that follows our general ‘three phase’ level structure, with an initial introductory fight followed by two more intensive ones with swarms of enemies and many bullets flying around.
Level 6 – Boss
Finally to finish off the Act the player fights a small boss. The game is now in full bullet hell mode and this fight is primarily a dodging exercise. The hit box of the boss did cause some problems. It is only slightly larger than a regular large enemy and this caused issues for some new players as they couldn’t concentrate on dodging and adjust their aim to track the boss as it wandered across the screen. This was fixed by reducing the distance the boss could move, but only on easy or normal difficulties, leaving its original form for hard/absurd difficulty.
General notes on Tutorials
Our main lesson about tutorials is that you will never make everyone happy. Every gamer has a particular type or style of tutorial that they like or loath. Some like text on the back of a wall that they can passively read or ignore. Some want the game to pause and force them to read things. Some like no tutorials at all. Some of your players will dislike the way you teach them and you just have to live with that.
Your aim should be to teach the player as quickly and precisely as possible and interrupt the game as little as possible whilst doing so. In Gunnihilation we decided to spread the tutorials out over an opening set of levels, with tutorial areas separated by proper gameplay. Each tutorial area was a small area that required precise actions from the player to proceed.
As for tutorial text, we decided on a half-way measure. If the player has never completed the first act of the game, touching a tutorial sign automatically triggers it, forcing the player to tap through and (hopefully) read it. They can then use the sign again to read it again. However if they have cleared the first act and are replaying it, the signs do not automatically trigger on touch, and the player can sprint past without interruption.
These are some sketches made up for the original version of the game, before the Flash Prototype was started. They are far more complex and interconnected that the final version, with many features such as key-hunts, angled surfaces, complex movement and special abilities being removed from the design as it was simplified and streamlined down to a purer arcade experience.