Several months ago I began working on a game that would combine elements from three classic games: Choplifter, Kickstart, and Defender. Unfortunately, I was never able to figure out how to use Gamemaker to simulate a vehicle going up and down slopes, so I'm giving up and moving on to something else. However, I thought it was a good enough idea to try to document here, perhaps in hopes that someone with better programming and/or math skills can pick this up or help me develop it.
Game type: 2D action.
Story: You are a paramedic dispatched to Planet Pharmacopia, where a disaster has happened. The planet is home to PharmCore, the galaxy's biggest and most profitable pharmaceutical R&D lab. Unfortunately, their latest project, a genetic treatment to allow humans to survive in the intolerant atmospheres of alien worlds--has gone horribly wrong. The monkeys the scientists were experimenting on have escaped (using the scientists' own jet packs) and are wreaking havoc on the scientists and innocent families living on the surface. The monkeys have destroyed all the remaining jet packs and even the bridges between domes, and the planet is too distant to expect help anytime soon. It's up to you and your SAARV to navigate the terrain, evade or destroy the monkeys, and bring the innocent people to PharmCore's Mobile Emergency Stations.
Game goal: Rescue people trapped in various locations on a multi-screen map (think Defender) using your SAARV (Shock-Absorbent Assault & Rescue Vehicle). The vehicle looks something like a hummer but with bigger wheels. The vehicle does not jump by itself, but instead must get across pits by building up speed and hitting ramps. It also has a cannon (that either fires straight up or perhaps is controlled with the mouse or by player 2) for dispatching the mutated monkeys. The monkeys, meanwhile, are dropping radioactive waste (use your imagination) on the civilian domes, slowly destroying them. If they are destroyed, the people inside don space suits and come running out. The monkeys then swoop in, pick them up, take them far up into the air, and drop them to their deaths. You have to get to the bases first, collect up to three humans, and get them back to the designated pickup facility on each level.
Difficulty Escalation: The early levels have no monkeys, or at least no monkeys that are dropping bombs or picking up humans. There are, however, ramps for the player to jump off of and get a feel for the ground mechanics. Later levels have, of course, more monkeys, more bombs, more people to rescue, etc., as well as more pits. The hardest levels have destructible terrain that are broken by the monkey's bombs, requiring more precise use of ramps. There is also a boss that must be destroyed. He is three monkeys combined into the SuperChimp, who can drop bombs as well as pick up the SAARV and throw it (resulting in massive damage).