I'd never heard of it (and haven't subsequently been able to find out anything useful about it), but it did make me want to play an Atari ST game of the same name that I remembered being very fond of in the late 1980s.
The ST Bellum, which as far as I can establish is no relation to the A400 one, was a PD game created by the immortally-named M. Goss-Custard, that had shown up on a disk of ("Legally-purchased commercial software" – Ed) I'd ("Bought in a shop" – Ed) at some point during my ST gaming phase.
It's a Galaga derivative – or more accurately a Gaplus derivative, given that it allows the player's ship a large amount of vertical as well as horizontal movement – but playing it now it reminds me very much of the splendid Xbox Live Indie game Decimation X.
It's not just the particle effects when your ship takes damage that do it, either, nor the frightening barrage of enemy fire that descends on you in later waves. The whole ethos and balance of the two games feels oddly similar too. In Bellum you can also get shot, shield and speed upgrades, the twist here being that as your ship takes damage, you lose the upgrades.
Keep it largely intact (or keep collecting the repair icons, which I've only just discovered are supposed to depict spanners) and you can hold onto and improve your firepower. Take a lot of hits, though, and you'll have to fight off the alien onslaught with a feeble popgun moving at snail's pace.
The way Bellum really reminds me of Decimation X, though, is that in both games you can recover from even the most seemingly hopeless position. In Decimation X collecting a shield pickup can buy you a few vital seconds to power up, wipe out a wave of invaders and earn an extra life or icon shower to get you one step ahead of the enemy again.
In the same way, dodging with your crippled ship until a spanner appears in Bellum can grant you a period of grace just long enough to grab the triple laser that will in turn create the breathing space to destroy another alien attack and get another spanner and so on, clawing your way hand-over-hand back to a position of strength.
Both games also make you want to keep playing just to see how insane the next wave is going to be, as well as to beat your high score. While there are many superficial differences, if you've played Decimation X, give Bellum a shot and then try telling me you don't see the DNA.
I DARE YOU.