Blaze is a retro/minimalistic styled sci-fi first person flight/shooter action game. The game can be played almost single handedly with just mouse. It's about shooting a lot of alien things (in semi-randomized missions?). The alien things are trying capture all your base, and have already captured at least half of it. You have to defend the base and capture the alien controlled areas back. Or something like that...
This level has 3 portals into 3 other levels. Then you can play the levels in pretty much whatever order you want. You can also play them again. Player will also return back to the correct portal in the HUB level. The other levels could also have some connections, but not as much as the HUB levels.
Monsters and stuff will respawn going back to levels, but there could be some alternate monster layouts, which could change depending on player's status. The HUB levels could have some monsters too.
Note: it's not a final quality level.. as in the first HUB should have more than 3 portals... and wouldn't hurt to have some more details.