You have to understand this game to enjoy it. It is NOT Atari Lunar Lander, you only control main descent thrust, angle thrusters are automatic. You have to watch your speed and especially your distance to target and not over or undershoot. If you do it's almost impossible to make it to the target, you'll either run out of fuel or altitude. Just first try and get distance to slow to near zero, then just gently tap the throttle on the way down watching your alt & descent speed. It's not as easy as it seems!
One thing, the success/fail sound files are too long, you get tired of waiting for them every time!