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Back when Sega went a bit crazy and released a Game Gear console for ants, it also commissioned the legends at M2 to produce an Aleste sequel tailored for that same hardware.
GG Aleste 3 ended up being one of the best shooters on any handheld, and was included in the Aleste Collection for modern-day systems. Sadly, it was never made available on its own, either via a digital download or (as I'd hoped) as a physical Game Gear cartridge (Sega produced a one-off cart for internal use, but it was never sold to the public as far as I can ascertain).
We've already seen the game released as a ROM which is playable on original Game Gear systems via a flash cart, and now it's the turn of the Game Gear's home console sibling, the Master System.
A new hacked version of the game has been made available which can be played on Sega's 8-bit home console. However, as with the Game Gear ROM release, if you decide to download this version, I implore you to support the game financially by purchasing the aforementioned Aleste Collection if you haven't already.
Sega really did take a punt on this game, and if we want to see more cool stuff like this from the company, we need to vote with our wallets and show them there's a market – even if it doesn't come out on precisely the systems we'd want it on.