10tons tends to make smaller scale games and you feel it sometimes but I've had a great time with quite a few of their other shooters too. You used to be able to get this bundle for cheap from fanatical sometimes, not sure if that is still the case. They are best known in the modern era for Tesla vs Lovecraft which doesn't show up in this bundle. https://store.steampowered.com/bundle/428/10tons_Shooters/

There have been a few attempts to make open source versions of Crimsonland and I had a good time with Violetland https://github.com/ooxi/violetland

I can second this! The game was influential enough to cause multiple people being involved in recreations