They have some game stopping bugs (or better, game escaping, they break the plot). It's handy to have a list of them at the start.
The first game can be broken by setting fire to some spider eggs, that would eventually fill the dungeon with smoke (that killed you, without counter and you need to pass through it sometimes).
The second game has some too, some intentional - but with indication (hardcore) some not - don't ask the right question from a information broker ("travel" i think) on one of three opportunities and you're hosed - can't get out of the city. If you win the fight after you do finally get out of the city, you'll break the plot (haven't personally tried this one out, seems unlikely it is "broken", since the item in question is used automatically when you need it and approach the right place. Maybe it's only the plot-line that is broken and you can jump ahead if you know what to do - this would be good since it would make the game more non-linear). The plot itself also seems incomplete, somehow. Three i'm doing now.
The main quest in blade of destiny is timed, and there are two timed quests in star trail. The MQ limit is generous, the star trail not so much.
You can lose your items, but it's never necessary to lose your magic items to progress (except one in that bug above i guess), these are alternative paths or just bad luck. One of my favorite items is the "Travia amulet" (makes you immune to thirst and hunger. Though getting hungry and thirsty is one of the most exciting parts of the game, at least like this one of the characters could survive and carry the corpse of a companion to the temple (only one, the others are dead if you don't have enough people living - you need to unjoin them i think). There is another two that make this even more convenient, but you need to do specific hard things. The items transfer between games.
You have to have lots of time and patience to do these games. NPC's are all over the town, before realms 3 they only allowed 3 questions a day even if you needed the information (and there is a LONG list of questions you accumulate), and the way to find out about where people live is ask in taverns or search the whole city.
I love the first one the best. It's like a more rigid darklands.
You need to be very disciplined and read the manual. Diseases can kill you dead easy: in my first game i was constantly getting them and using my druid to cure them, but this is unnecessary and harmful, since they can drain your stats. Better is prevent them by having a cooking pot, warm clothes, blankets, tableware, forks, blankets etc. You can avoid most of them except the very annoying battle fever (maybe it too, if you have the magic to heal before combat ends).
When you encounter a suspiciously strong enemy/encounter try to identify his drops. Things that are magical look indistinguishable from a iron sword mostly.
For gods sake get a magician with the tranversallis spell.
