Master System recommendations?

So, I bought a Sega Master System a couple of months ago, played the Hang On port that it came with for about a half hour, and then shelved it. I’d like to play it again, but I’m wondering what some good games are for it.

I’d prefer exclusives, but the system appears to be a huge port machine, with almost nothing but ports of arcade and Genesis games. Are there any good games for the Master System that only came out on it?

Alex Kidd in Miracle World - I like it more than Super Mario Bros., it’s a platformer with rock-paper-scissors?
Fantasy Zone - shooter that has cute graphics and is RIDICULOUSLY DIFFICULT.
Phantasy Star - the reason I bought a SMS, I assume you know about it. Oldschool RPG in a sci-fi setting with the best graphics on the console. Also: expensive
Space Harrier - I LOVE THIS GAME! You can get the arcade experience on 32X, Saturn, and either Shenmue game but it is worth mentioning anyway?
Bubble Bobble - Addictive arcade game. There’s some heavy blinking with the graphics but it’s generally considered the best home version of the game.
Ys: The Vanished Omens - this is the only part of the Ys series I’ve played and I think it’s great. It’s an overhead action-RPG similar to the original Zelda (only way better in countless ways IMO).
Zillion - this game is long and tough and I’ve never beaten it. But it is pretty fun. It’s a side scrolling action-adventure game? (In the real sense of “action-adventure”.) So if you like games with a heavy exploration element, this might be up your alley.

I considered this, but it looked a little too ‘cute’ for my tastes. I might check it out.

Ah, I forgot this was a Master System exclusive. I often find old-school RPGs to be unrewarding, but if it’s breezy, I’ll definitely pick it up.

Never heard of this before, but after looking it up, it sounds like something I’d really enjoy. I’m a big fan of the Metroid/SOTN style of adventure. Will definitely try this out.

Thanks for the suggestions!

Sonic 2.

(Both of which are very much different to their Genesis counterparts, and hard as nails.)

Wonder Boy 3 (or Wonder Boy: The Dragon’s Trap) is also good. I’m replaying it just now.