R-Type on the Sega Master System is an 8-bit port of the classic arcade horizontal shoot-em' up. There is a lot of game here that they tried to bring over and they largely succeeded. R-Type features amazing visuals, memorable music, and frantic action. The aspect that really sets R-Type apart is use of a separate "Droid Unit". This unit can be upgraded (featuring different firing types when attached), separated while continuing fire, attached to the front or rear of your ship, and also acts as a kind of shot absorbing unit. Droid control, in addition to your ship control, is critical and, fortunately, the controls in this game are tight. Fighting through R-Type reveals a variety of enemies and bosses with amazingly diverse and creative environments. Long story short, there is a lot of positives to say about the game.
However, that doesn't mean it is all perfect. Perhaps the most glaring gameplay issue is the difficulty, which is high even by 8-bit standards. You can tell that this game originated as something built to have you spend quarters on each play. You do have the ability to use continues, but after dying you lose your power-ups which can leave you in a really tough or almost impossible spot sometimes. Also, they really leaned on flickering to keep things running on an 8-bit system. Most of the time, this is just an annoyance, but when things get really hectic you can have some of the enemy shots start flickering in and out which really just adds to the already high difficulty level. Overall, R-Type is one of the best shoot-em' ups on the Sega Master System. However, it isn't perfect and better ports of the game are available on other systems.