Another Game Boy Player's Guide game, and one I'm surprised I never posted about already. I actually got this game as a kid, one of the ten or so Game Boy games I ever owned. Unfortunately, out of those ten-ish, this was probably the one I got the least out of. I think I played it a grand total of maybe 2-3 hours at the most, and was pretty much done with it in one day. It's a very short game and doesn't pose any particular challenge, especially compared to other games in this series. Still, it's worth a look.
The R-Type series, from Irem, was sorta the Ross Perot of the shooter universe circa the 1990s. Not as popular or well-known as Gradius and not as beloved by the hardcore as the vertical Compile games. It has a number of innovations that set it apart from (and even surpass at times) the Gradius games.