We may have to agree to disagree on altered beast. I didn't notice bugs. As for slow... that's altered beast. It's a pretty slow game.
I'll be honest, I hate most Alex Kidd games. But one has to separate things one dislikes from bad. Lost stars was an arcade game. It was an arcade game and thus a race against the timer. It's very different but not shovelware. It is my least favorite Alex Kidd. But it was not incompetent or put out without thought. It just is not my type of game.
High Tech World was actually a very popular game from my understanding in Japan. It's original name is anmitsu hime. SEGA thought the anime theme would not do well in the west and reskinned it. Basically, they super mario 2'd that shit. Still not my type of game, but just like Mario 2, I can look past that I don't like it and notice that it is not a bad game. It just is not one I like.