Oh, gee, where else has spring sprung? Right here, of course! In the Steam Spring Sale!
From now until March 21 at 10 AM Pacific, save 25% on Battle Rockets and 45% on Ultra Mission.
Both games are compatible with Windows and Linux, including Steam Deck!
https://store.steampowered.com/app/2499330/Battle_Rockets/
https://store.steampowered.com/app/1940350/Ultra_Mission/