Before Cruise Planet, the indie game that I’m working on now, there was a smaller version of the game made for college in the fall of 2021. Tasked with making one of my first games over the course of three months, my idea was to make a shoot-’em-up (think arcade shooting games that were most popular in the 80’s-90’s) with a roguelike structure.
In this game, the player’s ship shoots enemies, gets money from them, and obtains items by either finding them in chests midway through each level or buying them in shops. The item is a cornerstone of the modern roguelike, being one collectible randomly picked from a pool of others that boosts your abilities in a way, but items are often given out after a level, instead of in the middle of one.
I chose to put the chest at the midway point because it reflects the ebb and flow of a good difficulty curve, which in video games is more often a line with subtle hills and valleys instead of a straight slope. In Cruise Planet Legacy, the difficulty is bumped up when starting a new level, when the player encounters challenges in the form of new enemies and waves of them. Difficulty then gets a bit lower when they acquire a new item midway through the level, only for it to bump up again at the start of the next level. Compared to a game where the difficulty is always slowly rising, a difficulty curve like this is more noticeable to the player and gives them breathers between a game’s hardest points.
The game’s UI reflects all that is needed: the player ship’s current health, money, and inventory of items. However, I also implemented a combo system in this game, shown on the top right in this image, in the form of a badge that ranks up as you destroy enemies but is reset to zero when you miss one or take damage. Keeping up a good combo, and thus playing the game well, is rewarded by adding a bonus to how much gold enemies drop. However, it’s not a drastic bonus, adding up to one and a half extra coins on average for each enemy destroyed on the highest rank of combo. This way, if the player loses their combo they can still bounce back from their mistakes a few times.
After publishing one of the game’s milestones, I received feedback stating that one of the enemies, which appears at the top of the screen and quickly moves down to the bottom, was too hard to deal with. Despite having a small sound effect to indicate its arrival, the enemy didn’t give you any clues as to where it would be coming from. As it had a considerable amount of health, you often couldn’t deal with it quickly enough and it would be missed, making the player lose their combo or worse, collide with it and take damage.
My solution to this was to add a little warning effect that appears when the enemy is approaching. I was inspired by the missiles in Jetpack Joyride, which while fast, always let you know they are coming with an exclamation point, perfect iconography for a warning that should take up only a small amount of space on the screen. I liked it so much that I also applied this effect to a different class of enemies, small spinning gears that explode in one hit but move directly towards the player.