$450? I'm not really sure. I'm still new to the EM world myself. EM prices seem to fluctuate more than more modern machines. I just bought a non-working El Dorado on Labor Day weekend for $900. My El Dorado back glass is flaking like this Space Odyssey is. Space Odyssey is a pretty neat machine and definitely worth the effort to have as your first EM and to get your feet into the EM world. I'm currently working on a Fireball and I am thoroughly enjoying the EM side of things. What I like best is that the switches, relays, and coils are all probably good. I've only worked on 5 EM's so far, but they all have been able to return to flipping and playing games with hardly any money spent. The work has mostly been just taking things apart, cleaning, putting them back together, and adjusting switches. Stepper units and score motors can be a little intimidating, but there is a ton of help here and on YouTube.

grandy I'm still an EM novice, but I think you should look at the score reels and pay special attention to what the switches are adjusted to for the number 0 and number 9 positions. Usually one of the switches opens up on the 0 position so that the reel gets de-energized and stops moving. So if you have a known good score reel that is stopping at 0000, then look at the switch positions for the 0, 1-8, and 9 positions.

I would start there and see if that resolves it.

I was going to suggest like Pin-pilot did. I've had similar issues come up on my El Dorado with some of the player unit switches. In my cases tightening the switch stacks helped or else a slight adjustment of the switch gap.

Got my son-in-law's Space Mission working last weekend after working on it for a few hours every night for a week. It's a pretty fun machine and has a lot of features to it. Since I have a Fireball EM and El Dorado, Space Mission's spinner is lots of fun.

I'm waiting for my order from the Pinball Resource to arrive and I have a few minor repairs to make this weekend. New flipper bats and a new Lock Relay Coil. Should be able to move the machine back to my daughter/son-in-law's house over the weekend so they can begin enjoying it.

As far as game strategy, all I can figure out is that it is a good idea to hit the swinging target to light up the game features for double bonus, light the spinner for 1,000 a spin, and try to get an extra ball. The trick seems to not hit the swinging target after that so the features stay activated as long as possible.

I really like the 100,000 score lights for when you roll the score reels over. My Fireball, Time Zone, and El Dorado do not have that feature. Getting extra balls is fun too. I also get a kick out of making the knocker go off to award credits based on high scores and the after game match.

Jmxdc I'm certainly not an expert, but that sounds like a score reel problem. If the score reels for player one haven't been taken apart recently, cleaned, and switches cleaned and adjusted, that would be where I would start. Do the score reels keep spinning and not stopping? If so, that's related to the switches for when the score reels are at position 9 or 0.

This website is great and really helps me. Here is an explanation of the Williams score reel.

https://homepinballrepair.com/em-score-reels-williams/

I've had this problem on a few occasions.

"If the three switches do not open at zero, then the machine will not know that the score reels have reset. A side effect is that the Score Motor (in the cabinet under the playfield) will keep spinning."