Kerbal Space Program
- staging is incredibly important, and if you mess it up, you will end up jettisoning fully-fueled stages and thus not being able to transition from a sub-orbital ballistic trajectory into a stable orbit (your second stage just dropped off without firing or something), or inversely, unable to come back down from one (you just dropped off you third stage or whatever, which you intended to use for orbital maneuvers).
Same game - parachutes have only enough material and strength to bring a crew capsule to rest. Usually, the chute will flare open and promptly rip itself off your capsule under the extra strain.
Same game - solid rocket boosters are not fond of heat, and have a tendency to explode.
Same game - the larger the rocket, the less stable it will be when you launch it. You will need RCS thrusters or better still, control surfaces, in order to keep the thing pointed in the desired direction of travel, lest you end up nosing the thing over ten second into flight and having a spectacular collision with the ground.
Same game - SRB's are best jettisoned when they are EXPENDED. If you release them while they are under thrust, they tend to slam into your rocket with predictable results.
Same game - budget your fuel once you're in space. Running out of fuel will strand you, unless your trajectory will have you eventually scraping the atmosphere of Kerbin for an eventual landing.
Same game - RCS thrusters can be used in Translation mode as primitive retro-rockets (see above), but they have very low thrust ratings and your RCS tanks aren't very large. They're better than nothing at all, though.
Same game - it is best to change Periapsis when you're at Apoapsis, and vice versa, to minimize fuel use.
Same game - Orbital Inclination changes are best done in small amounts initially to ensure that you're not shifting it the wrong
Same game - if your rocket explodes on the launchpad, slapping more fuel onto it is not going to fix anything.
Happiness is zero-gee with a sinus cold.