Right then guys! Just completed UN Squadron
using 3 credits (feel free not to include this score if that voids it-I thought it was a reasonable 'real life' number of credits) about 3/4 an hour on, batteries red hot from the overclock and eyes twitching from FS1, I had 1,290,910 points.
You should be able to beat this if you can do the last couple of levels on one credit, but it's a start...
I noticed a couple of graphics errors along the way, a weird black square floated across the screen during Mission 9 (I've seen this in another shooter -where all the sprites appeared as squares but I can't find it again!), and the same weird glitchy horizontal lines that you get when you boot the game up were also to either side of the massive end-game boss.
I'm still trying to beat naples39's Robotron score! I've got into the 90k's a few times...