So, ever since Microsoft bought Mojang, they've been boiling the frog, and finally with the "Xbox accounts" and 1.19.2 the Java edition has reached surveillance state nightmare (however ludicrous that sounds for a game… it's still a game we play) parity with Xbox Live Arcade (aka "NAMBLA") and the inferior mobile/"Bedrock" edition, and it's really time to look for alternatives.
One such is MineTest, which is an open source blocky game engine, with easy modding in Lua. The base MineTestGame is a very simple peaceful/creative mode, which isn't that interesting, but mods change everything. One of the mod packs ("games") is MineClone2; it aims to recreate MC 1.12.2 with some improvements, while MineClone5 (I guess 3 & 4 fell into a swamp) is a much less stable fork that chases current features. Other games aren't concerning themselves with MC-like-ness at all, I'll look at some of those later.
Download the client from the MineTest page, then at the bottom bar hit + and type in MineClone, hit + on MC2. Back on the Main Menu, select the 2-grass-block icon from the bottom, the screen should change to show a MC2 logo, hit New to make a new world.
When I started testing MineTest, it was very laggy, the Mac display & input was completely broken. In 5.4, it got up to usable but not fun, with a really horrible input lag. In 5.6, just released on the 4th, it's actually playable! FPS rate is a little low (15-30 instead of the 30-60+ I expect), picking up/moving inventory can be sluggish, but the game is on par with any older edition of MC now.
MineClone2 can have some remarkable terrain, tho there's something a little off, I get broken Nether portals every few hundred meters in plains. The mobs are dumb but as dangerous as MC and I'm less skilled here. Villagers work, I don't have a proper screenshot of the village I've started trading with, I need to clear some land and fence it off, after I set up my next base near it. Animals are a bit odd, they're persistent but spawn in randomly on grass when you enter the area, there's a river below my base, and it's constantly splashing with sheep & llamas that fall in; I should build a lava blade trap for them. I've made a map, but it's uselessly small and can't be resized, but does point back home. The built-in minimap (hit M, repeatedly to cycle views) is very useful.
By default there's no access to debug. You can open the console, but no command shows coords AFAICT.
~/Library/Application Support/minetest/minetest.conf (probably ~/.minetest on Linux, WTF knows on Windows):
keymap_console = KEY_F5 keymap_inventory = KEY_TAB keymap_minimap = KEY_KEY_M keymap_mute = KEY_F10 keymap_screenshot = KEY_F2 keymap_toggle_block_bounds = KEY_F6 keymap_toggle_chat = KEY_F7 keymap_toggle_debug = KEY_F3 keymap_toggle_fog = KEY_F8
Or whatever keys you like for those. Now I can hit F3 and get a teeny text status of FPS & pos, hit it again and get full debug/lag spike data.
What I'd like is a bit more of Life in the Woods, or Super Hostile type modpacks, make survival hard and more complex, but with a gentler introduction than Feed the Beast etc. There is Exile in the ContentDB, and I kind of glazed over looking at the wiki, my one test of it I punched some sticks but couldn't make anything, then got blown up, but I'll run at it again.
There's not a lot of Youstubes or Twitches of MineTest yet, but there's a few "punch wood" demos, and a lot of what you know about MC just works in MineClone2.