Essentially Star Diver is a game involving a ship (The Sweeper) and alien formations (rock-like in nature) orbiting one or more stars. The objective of each level is for the Sweeper to knock the formations either into a Star (which makes them explode) or into the "edge of space", an artificial level boundary. This objective will change depending on the level. Harder levels require all formations to experience a fiery death to pass.
The game does not involve shooting of any sort, and even though it is an arcade game, it is slower in pace and based on accuracy and strategy. The sweeper also has no engines, and it achieves propulsion purely using gravity. Harder levels will take many attempts to complete using different strategies.
The Story is that the hostile alien formations have resisted all long range attacks known to man, hence the Sweeper was built to counter the threat to humanity. The sweeper is constructed almost entirely from Tungsten Carbide. It is therefore almost as hard as diamond and has an extremely high tolerance to heat, required to move in close proximity to stars. Is is built with the express purpose of attacking the formations physically and at high speeds.
Because it has no engine as such, the game wouldn't be much fun if the Sweeper simply crashed into the stars without any means of control! Therefore the Sweeper features an anti-gravity device which can render it immune to gravitational effects. By default this is turned on and the Sweeper therefore moves in a straight line. By tapping and holding the screen anywhere, the sweeper turns off its anti-gravity device and is then attracted by any celestial object, be it a star, black hole etc. The way that the Sweeper moves through the game world is by the player carefully controlling the orbit that it takes. In this sense Star Diver is essentially a "one tap" controllable game apart from using the Power Ups (see below).
The sweeper after smashing into a formation, changing it's orbit
Star Diver is also part physics simulation; the orbits of the formations are totally physics based, and collisions affect both the Sweeper and formations realistically. The Sweeper's orbits are also realistic and conservation of angular momentum plays a big part.
Each level has a "passing" score required to play the next level and a "perfect" score. Game progress is divided into a number of stages containing a number of levels each, with each stage accessible only if perfect scores are obtained in the preceding stages. There will be about 50 levels in the game, even though at the moment there are only 4 test levels.
The game also has two types of power ups, tractor beams (which temporarily allow the Sweeper to exert a gravitational pull on the closest formation) and gravity bombs (which can be placed anywhere and then exploded later, exerting a massive push on any formations within range). Some levels will provide one or more power ups at the start of the level.
Tractor Beam Power Up in action
Shall we blow it up now, captain?
The level ends when all formations have been eliminated (either way), or if the Sweeper is destroyed - this can happen when it smashes into a star, or hits the edge of space. Each level will take between a few seconds for introductory levels to maybe 2 or 3 minutes for challenging levels, so this is definitely a "snacking" type of game.
How does Star Diver control the difficulty of levels and keep things interesting and unique?
- Different sized formations with different mass, requiring different strategies
- Different sized stars with different mass, therefore changing the whole experience of the level
- Formations that are close to stars or very far away, requiring different strategies to remove
- The direction of travel of each formation in relation to the Sweeper
- Multiple stars and /or black holes that allow the player to change direction by travelling in a figure 8
- Other celestial objects such as planets that are on a collision course with formations that the player has to protect to pass the level
- Changing the objective of how formations need to be removed to either into star or into edge of space (easiest), only edge of space (harder) or only into stars (hardest)
I have so far built a number of levels for testing purposes ranging in difficulty, and I am happy to say that I am thoroughly addicted to my own game, especially the harder levels, which even after a lot of practice, I can only get perfect scores in once in maybe 10-20 games played.
I'll share in future posts what has been done, and what is still to be done. And there is quite a lot! One of the most valuable learnings from this process for me has been understanding what it takes to actually complete a game of any kind - the actual game mechanics are almost the smallest part of the overall process! It is natural to under-estimate the enormity of getting any reasonably polished game "really" complete.
